Cranks but no start – GM?

  • There are three very basic components that the engine, in your GM vehicle, needs to start and they are: air, fuel, and spark. When your 4.3L, 5.0L or 5.7L GM vehicle cranks but does not start, it’s because one of these components is missing from the mix.

What sensors can cause a car not to start?

A bad Crankshaft Position sensor is a common cause of no starts. The signal from this sensor goes to the PCM or ignition module that switches the ignition coil(s) on and off. If you have an RPM signal, a bad ignition module or PCM may not be switching the coil(s) on and off.

Why is my GMC truck not starting?

The most common reasons a GMC Sierra 1500 won’t start are a dead battery, an alternator problem, or failed starter.

Why is my car turning over but not starting?

If the car cranks when you turn the key, but the engine won’t start, it could be because fuel isn’t getting to the engine. One potential reason for this could be dirty fuel injectors. Over time, the fuel injector nozzles can become clogged with rust, corrosion or debris.

Can bad spark plugs cause crank no start?

Can Bad Spark Plugs Cause a Car To Crank But Not Start? If the spark plugs are old, worn, fouled, or damaged, they might not spark. When there’s no spark, there’s no starting.

How do you diagnose crank no-start?

Ignition timing on a no-start can be confusing, but it can still be tested by connecting a timing light, then watching the timing marks while an assistant cranks the engine. While this may or may not be base timing as specified by the manufacturer, it does let you know where the spark is occurring.

Will a crankshaft sensor keep a car from starting?

Issues Starting the Vehicle The crankshaft position sensor monitors the position and speed of the crankshaft and other parameters that play an important role when starting the engine. If the crankshaft position sensor is having a problem, the vehicle may have intermittent starting issues or not start at all.

What would cause a Chevy truck not to start?

The most common reasons a Chevrolet Silverado 1500 won’t start are a dead battery, an alternator problem, or failed starter.

What are the symptoms of a bad starter?

What are common bad starter symptoms?

  • Something sounds off.
  • You’ve got lights but no action.
  • Your engine won’t crank.
  • Smoke is coming from your car.
  • Oil has soaked the starter.
  • Look under the hood.
  • Tap the starter.
  • Adjust the transmission.

Why is my GMC Acadia not starting?

The most common reasons a GMC Acadia won’t start are a dead battery, an alternator problem, or failed starter.

What are signs of a bad spark plug?

What are the signs your Spark Plugs are failing?

  • Engine has a rough idle. If your Spark Plugs are failing your engine will sound rough and jittery when running at idle.
  • Trouble starting. Car won’t start and you’re late for work… Flat battery?
  • Engine misfiring.
  • Engine surging.
  • High fuel consumption.
  • Lack of acceleration.

Chevy 350 Cranks but No Start Problem

Kenny Scheer, an intern at Rollings Automotive, adjusts the harmonic balancer on a small-block Chevy to the position advised by the shop for the initial fire-up. It is preferable to over-advance the initial timing on a newly fitted engine in order to facilitate starting. Photograph courtesy of Rollings Automotive

QUESTION

I recently obtained a 1968 Chevrolet pickup vehicle with what seems to be a new 350-horsepower engine. It had been sitting for a long time and was in an undetermined state of repair. I was hopeful that it would start if I could get fuel and a spark. I checked to see that it was turning freely, then noticed that there was no spark. It all started with a coil replacement, followed by the distributor points, condenser, rotor, and cap. I’m getting decent spark at the points right now, and I’m getting 12 volts to the coil and points area.

1 hole, which I promptly fixed with tape.

  1. 1 and the next terminal on the cap, which is No.
  2. Due to the possibility that the mark is incorrect, I planned to use some sort of instrument to establish absolute TDC, but I don’t have a piston plunger or a TDC stop tool on hand.
  3. What are your thoughts?
  4. Through the use of email

ANSWER

A misaligned distributor with the harmonic balancer or a mismatched balancer and timing tab are the most common causes of a “cranks, but doesn’t start” problem on your Chevrolet 350 distributor installation. To the benefit of our readers, and with the assistance of the full-service professionals at Rollings Automotive, let’s start at the bottom of the complexity tree and work our way up. Is the engine receiving fuel? Although it should be self-evident, because you did not expressly state it, is the carburetor actually getting fuel?

  • Is the mechanical fuel pump generating any pressure?
  • Even if gasoline is getting to the carburetor, what happens to the carburetor’s float and choke settings, as well as the idle mixture adjustment?
  • Increase the engine speed while keeping the throttle half-way down (which opens the choke and helps get air into the motor).
  • Are you still operating a points distributor?
  • Typically, the yellow wire from an old stock harness is connected to this terminal.
  • “I’m getting 12 volts to the coil and points region,” you reply.
  • Under cranking situations, you must check the voltage of the battery.

The method Chevy momentarily sends full power to the coil on an old points system is through an additional “bypass” (typically yellow) wire that goes from the R-terminal on the starting solenoid to the coil positive (+); this wire is only “hot” when the engine is cranking; otherwise, it is not.

  1. The absence of the “R” terminal wire may result in insufficient voltage under the crank to start the motor.
  2. When running the engine, do not connect the old “R” bypass wire straight to the solenoid “S” terminal (which is likewise hot only when cranking), as this will result in about 9.5 volts backflowing from the coil (+) to the “S” terminal.
  3. If you must use a starter that does not have a “R” terminal, replacing the stock bypass wire with a Powermaster diode wiring harness (PN 600) will allow you to connect the cranking wire to the S terminal without experiencing any negative repercussions.
  4. While the engine is running, the unusual breaker point arrangement allows for point adjustment through a distributor cap window, which also offers access to alter the dwell angle using an Allen-head adjuster screw (arrow).
  5. Again, this is self-evident, but you need a spacing of around 0.016-inch.

This procedure is the same for any early Delco small-cap distributor (see “How to Adjust Points Ignition on a Corvette” for further information.) If you are able to get the engine to start, fine-tune the initial points setting by rotating the little Allen screw within the metal window of the cap to 30 degrees, as indicated by a dwell meter, and restarting the engine.

  • 1 cylinder’s spark plug hole (3 feet because you can hand-crank the engine by the balancer bolt while holding the other end of the hose up to your ear).
  • Gasket under the part number PN 8016MRG.
  • TDC firing, or something near to it for government work, may be achieved by slowly rotating the engine up by hand until the ‘driver just stops moving.
  • The balancer’s “zero” mark should line with the timing tab’s 16-degree BTDC mark at this point if you have a decent balancer and a matching “proper” timing tab at this point.
  • Photographs courtesy of Rollings Automotive Is the rotor of the distributor properly oriented?
  • 1 when it is approximately 16 degrees back to the center of the compression stroke at the harmonic damper.
  • Loosen the hold-down nut on the distributor bracket and spin the distributor body until the rotor is aligned with the No.

If you are unable to align the rotor, the distributor has been placed incorrectly.

1 terminal, as long as the cap terminals are still in the right firing-order sequence (for a Chevy, 1-8-4-3-6-5-7-2, clockwise rotation).

1 terminal on the cap.

1 wire terminal on a factory Chevy big-cap HEI installation is normally the second wire terminal clockwise from the rectangular section of the coil cover extending out of the housing where the external wires are connected to the coil.

1 terminal may be on either side of the metal window on the right or left.

(as of June 2020).

1 cap terminal, housing, and rotor should be in alignment as well.

Alternatively, if you run out of rotation space, you may uninstall and reload the distributor.

It is necessary to begin reinstallation counterclockwise from the desired fully-installed position, which is about 1-11/16 inches measured around the housing’s body for the small-cap Delco and 2-1/4 inches measured around the housing’s body for this big-cap HEI.

Rollings recommends applying downward pressure to the housing as a partner gently spins the engine in a clockwise direction until the unit is entirely lowered into its final position.

When using a factory-style balancer, where the outer inertia ring is separated from the inner ring by a rubber strip, the outer ring may “wander” in relation to the inner ring at some point during operation.

On a points system, the timing will gradually get more accurate over time as the points wear away.

This is called a TDC mark.

It is possible that the balancer has not been spun and that the timing marks at the balancer are not aligned with where you believe TDC is.

Is your harmonic balancer and timing tab out of sync?

The timing tab and the balancer must work together as a “matched” pair.

An 8-inch-od balancer pointer will not have the time marks appropriately spaced for a smaller 6.73-inch-od balancer since the pointer was designed for the larger balancer.

Then there are many balancer timing mark positions to consider. However, there have been a few “oddball” balancer placements over the years as well, including the following three Chevy harmonic damper timing mark sites:

  • A misaligned distributor with the harmonic balancer or a mismatched balancer and timing tab are the most common causes of a “cranks, but doesn’t start” problem on your Chevy 350 distributor installation. But, for the sake of our readers, and with the assistance of the full-service professionals at Rollings Automotive, let’s start at the beginning and work our way up the complexity tree. Is there any petrol in the engine? – However, because you didn’t expressly state it, is the carburetor receiving gasoline, despite the fact that it should be. Is there any new (as opposed to stale) gasoline in the tank? Whether or not there is any movement from the mechanical fuel pump. Is there a blockage in any of the fuel filter? Assuming that gasoline is making its way into the carburetor, what happens to the carburetor’s float settings, choke settings, and idle mixture adjustment? The first “cowboy” check, according to Norm Rollings, is to shoot around 8 ounces of diesel starting fluid into the top of the carburetor to make sure everything is working properly. Increase the engine speed while maintaining a half- throttle (which opens the choke and helps get air into the motor). It’s important to check the fuel-supply system and carburetor settings if the engine starts for a brief period of time and then dies. Do you still have a points distributor in your business? It is important to ensure that your General Motors starting solenoid has a “R” bypass terminal (arrow) that only feeds the coil with an uninterrupted supply of 12 volts while the vehicle is being started. This connector is connected to the yellow wire of an old stock harness. Tommy Lee Byrd provided the photograph. When it comes to cranking and running, is the voltage correct? “I’m getting 12 volts to the coil and points region,” you explain. “Is this correct?” The results of a static voltage check are not conclusive if the test is only done once. Under cranking situations, you must check the voltage of your battery. A full battery voltage (12 volts) under cranking but only roughly 9.5 volts under “Run” is required to avoid burning out the ignition points on an ancient Chevy points system. During cranking, a special “bypass” wire (typically yellow in color) connects the R-terminal on the starting solenoid to the positive (+) terminal on the coil. This wire is only “hot” when the engine is running, and it prevents the coil from overheating. After the engine starts, the bypass wire is added to the standard ignition switch to coil (+) wire, which after the engine fires exclusively supplies power under normal “run” conditions but at a voltage lower than 12 volts because there is (or should be) a voltage-reducing ballast resistor or resistor wire in the circuit. There may not be enough voltage under the crank to start the motor if the “R” terminal wire isn’t attached. If your “later” engine came with a starter, be aware that starters from the mid-1970s on up may not always have a “R” terminal because a bypass isn’t required with HEI big-cap breakerless distributors or computer distributors, which require a full 12-volts under all conditions and use a nonresistor 12-gauge pink wire all the way from the ignition switch to the coil. When running the engine, do not connect the old “R” bypass wire straight to the solenoid “S” terminal (which is likewise hot only when cranking), as this will result in about 9.5 volts backflowing from the coil (+) to the “S” terminal. Ideally, you should use an earlier or universal-type starter that still has a “R” terminal or an analogous bypass circuit to start the vehicle. Replacement of the standard bypass wire with a Powermaster diode wiring harness (PN 600) will allow you to connect the cranking wire to the S terminal without experiencing any negative repercussions if you must use a starter without a “R” connection. Delco-window-cap Remy’s distributor was considered a technological accomplishment at the time it was introduced in the market place. Using the unusual breaker point design, you may modify the points while the engine is running by seeing through a distributor cap window, which also lets you to alter the dwell angle using an Allen-head adjuster screw (arrow). Cardone provided the image. The ignition points (points distributor) have been correctly gapped. The requirement for a 0.016-inch gap is, once again, blindingly evident. The gap may be set by manually turning the engine over until one of the eight lobes on the distributor shaft cam has completely expanded. (“How to Adjust Points Ignition on a Corvette” explains how to do it
  • It’s the same procedure for any early Delco small-cap distributor.) You may fine-tune your initial points setting by rotating the little Allen screw within the cap’s metal glass to 30 degrees, as shown by a dwell meter. If you can get the engine started, you can go to step 2. Notice that changing the dwell during running conditions alters the base time, so make sure you have the correct dwell/points-gap settings first.) Working while blowing whistles is a good thing. The insertion of a low-cost TDC whistle or even three feet of flexible common 3/8-inch rubber fuel-line hose inserted into the No. 1 cylinder’s spark plug hole will bring you very near to TDC (3 feet because you can hand-crank the engine by the balancer bolt while holding the other end of the hose up to your ear). TDC whistles are available from Mr. Gasket under the part number PN 8016MRG, which stands for “flexible TDC whistle.” Rollings Automotive is pictured. When the TDCC whistle blows, remove it and insert a long screwdriver into the TDCC cylinder. TDC firing, or something close to it for government work, may be achieved by slowly rotating the engine up by hand until the ‘driver’ simply stops moving. Counterclockwise turn the engine the opposite direction 16 degrees and repeat the process. The balancer’s “zero” mark should line with the timing tab’s 16-degree BTDC mark at this stage if you have a decent balancer and a matching “proper” timing tab. if not, look for a delaminating balancer or a balancer/timing tab team that isn’t working correctly. Rollings Automotive Photographs Is the rotor of the distributor in the proper orientation? During the compression stroke, when the timing pointer is at about 16 degrees BTDC, the rotor tip should point to the No. 1 terminal on the rotor. In order to get an engine to start, the initial timing does not have to be extremely precise. However, starting the engine directly at TDC (zero mark) is too late
  • “late timing” results in an engine that is difficult (or impossible) to start. Allowing for the rotor to line with the No. 1 cap terminal, loosen the distributor bracket’s hold-down nut and spin the distributor body. It is likely that the distributor has been placed incorrectly if you are unable to align the rotor properly. Alternatively, any cap terminal can be designated as the No. 1 terminal, provided that the cap terminals are still in the right firing-order sequence (for a Chevy, 1-8-4-3-6-5-7-2, clockwise rotation). If everything is in order with the balancer, align the distributor housing with the No. 1 terminal on the capacitor. Number 1 is normally the second wire terminal clockwise from the rectangular section of the coil cover that protrudes out of the housing, which is where the external wires are connected on a standard Chevy big-cap HEI installation. Rollings Automotive is pictured. According to the year and model of the small-cap early Delco points distributor, the stock placement of No. 1 terminal may be on either side of the metal window, or it may be in the middle. Cardone refurbished aluminum-housing small-cap Delco that fits a 1968 C10 pickup 327 is still available for $44.99 at AutoZone (as of June 2020). Cardone provided the image. As long as the balancer zero mark and timing pointer are both aligned at 16 degrees BTDC, the distributor’s No. 1 cap terminal, housing, and rotor should all be in alignment as well. Rollings Automotive is pictured. The housing should be rotated as necessary to obtain line-up—counterclockwise for more advance, clockwise for more retard. Remove and replace the distributor if you run out of rotational space. Rollings Automotive is pictured. Auto-rotation of the assembly occurs as the distributor shaft engages and disengages from the cam gear. It is necessary to begin reinstallation counterclockwise from the intended fully-installed position, which is about 1-11/16 inches measured around the housing’s body on the small-cap Delco and 2-1/4 inches measured around the housing’s body on this big-cap HEI. The rotor and shaft will “cam over” clockwise when it encounters the gear, but the rotor and shaft may still not seat completely against the intake manifold owing to misalignment of the oil pump driveshaft’s tangs. It is recommended to apply downward pressure to the housing as a partner gently spins the motor clockwise until the unit is entirely lowered into position, according to Rollings. Spun balancer? Image courtesy of Rollings Automotive When using a factory-style balancer, where the outer inertia ring is separated from the inner ring by a rubber strip, the outer ring may “wander” in relation to the inner ring at some point during the operation. One indication that this is occurring is if the time continues roaming – it will not stay in the position you have set it to. On a points system, the timing will gradually get more accurate over time as the points wear away.) For hot rods that use factory balancers, an old-school method involves painting a white or yellow vertical line down the side of the balancer that runs parallel to the TDC mark on the balancer edge. When you start the engine, check to see if the line down the side of the engine wanders or doesn’t stay correctly aligned with the timing pointer when you crank it over. It is possible that the balancer has not been spun and that the timing marks at the balancer are not aligned with where you believe TDC is. In this case, the balancer and timing tab will be mismatched or incorrectly aligned. Harmonic balancer and timing tab that are not in sync? Small-block Throughout the years, the positions of Chevy balancer timing marks and the timing tabs that correlate to them have changed slightly. In order for the timing tab and balancer to work together, they must be “matched.” There are many types of timing tabs. Some are attached to the timing cover by bolts, while others are welded to the cover. An 8-inch-od balancer pointer will not have the time marks properly spaced for a smaller 6.73-inch-od balancer since the pointer was designed for the larger balancer. If a welded tab is required, this may necessitate the use of a new timing cover (or not needed). Afterwards, there are many balancer timing mark places to consider. The following three are the most frequent Chevy harmonic damper timing mark positions—although there have been a few more “oddball” balancer placements over the years:
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A misaligned distributor with the harmonic balancer or a mismatched balancer and timing tab are the most common causes of a “cranks, but doesn’t start” problem on your Chevrolet 350 distributor setup. But, for the sake of our readers, and with the assistance of the full-service professionals at Rollings Automotive, let’s start with the basics and work our way up the complexity tree. Is there fuel in the engine? Although it should be self-evident, because you didn’t specifically state it, is the carburetor actually receiving fuel?

  1. Is the mechanical fuel pump generating any energy?
  2. Assuming that gasoline is making its way to the carburetor, what happens to the carburetor’s float settings, choke settings, and idle mixture adjustment?
  3. Increase the engine speed while maintaining a half- throttle position (which opens the choke and helps get air into the motor).
  4. Are you still in business as a points distributor?
  5. This connector is connected to the yellow wire of an old stock harness.
  6. What is the proper voltage under cranking and running conditions?
  7. If it is only a static voltage check, it is not conclusive.
  8. It is necessary to have full battery voltage (12 volts) under cranking but only roughly 9.5 volts under “Run” in order to prevent burning out the ignition points on an old Chevy points system.

The bypass is in addition to the standard ignition-switch-to-coil (+) wire, which, after the engine fires, exclusively supplies power under normal “run” conditions, but at a voltage lower than 12 volts because there is (or should be) a voltage-reducing ballast-resistor or resistor wire in that circuit.

If your “later” engine came with a starter, be aware that starters from the mid-1970s on up may not always have a “R” terminal because a bypass isn’t required with HEI big-cap breakerless distributors or computer distributors that require a full 12-volts under all conditions; they use a nonresistor 12-gauge pink wire all the way from the ignition switch to the coil.

  1. Ideally, you should use an older or universal-type starter that still has a “R” terminal or a similar bypass circuit.
  2. Delco-window-cap Remy’s distributor was considered a technological advance when it was first introduced.
  3. Photograph courtesy of Cardone Are the ignition points (points distributor) appropriately gapped?
  4. Set the gap by manually turning the engine over until one of the eight lobes on the distributor shaft cam has fully expanded.
  5. NOTE: Changing the dwell under running circumstances also alters the base time, so make sure you have the right dwell/points-gap settings first.) Use whistles while you’re working: An cheap TDC whistle or even 3 feet of flexible common 3/8-inch rubber fuel-line hose put into the No.
  6. Mr.
  7. Image courtesy of Rollings Automotive When the TDCC whistle sounds, remove it and insert a long screwdriver into the TDCC hole.

Rotate the engine 16 degrees counterclockwise in the other direction.

If this is not the case, look for a delaminating balancer or a mismatched balancer/timing tab team.

When the timing pointer is around 16 degrees BTDC on the compression stroke at the harmonic damper, the rotor tip should point to the No.

Initial timing does not need to be extremely precise in order for an engine to start—but starting the engine directly at TDC (zero mark) is too retarded; “late timing” results in an engine that is difficult (or impossible) to start.

1 cap terminal.

Alternatively, you can designate any cap terminal as the No.

Once the balancer has been sorted, align the distributor housing with the No.

On a standard Chevy big-cap HEI installation, No.

Image courtesy of Rollings Automotive Depending on the year and type of the small-cap early Delco points distributor, the stock placement of the No.

Currently, AutoZone is offering a Cardone remanufactured aluminum-housing small-cap Delco that would fit a 1968 C10 pickup 327 for $44.99 (retail price) (as of June 2020).

1 cap terminal, housing, and rotor should likewise be aligned.

You can remove and replace the distributor if you run out of rotational space.

It is necessary to begin reinstallation counterclockwise from the desired fully-installed position, which is about 1-11/16 inches measured around the housing’s body for the small-cap Delco or 2-1/4 inches measured around the housing’s body for this big-cap HEI.

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Rollings recommends applying downward pressure to the housing while a partner carefully turns the motor clockwise until the unit is entirely lowered into position.

The outer inertia ring of a factory-style balancer that is separated from the inner ring by a rubber strip may occasionally “wander” in relation to the inner ring.

(On a points system, the timing will alter gradually over time as the points wear away.) The old-school approach of painting an alignment line along the side of the balancer, lined with the TDC mark on its edge, is useful when utilizing factory balancers in a hot rod.

It is possible that the balancer has not been spun and that the timing marks at the balancer are not aligned with where you believe TDC is.

Is your harmonic balancer and timing tab mismatched?

The timing tab and the balancer must work as a “matched” team to be effective.

The time markings on a pointer designed for use with an 8-inch-od balancer will not be properly spaced on a smaller 6.73-inch-od balancer.

Then there are a variety of balancer timing mark places to choose from. However, there have been a few “oddball” balancer placements over the years as well, including the following three:

  • 1969 to late 1970s with some continuous use through 1995: The timing mark is located approximately 10 degrees counterclockwise from the crank keyway on the clock face. When the No. 1 piston is at TDC and firing, this places it approximately 35 degrees off top-down vertical. The majority of performance and racing aftermarket dampers, as well as the majority of bolt-on nonadjustable timing tabs, follow this design.

On practically all Chevrolets from 1969 until at least the late 1970s, as well as some engines from even later years, this is the most frequent small-block balancer timing mark/keyway offset. There’s a time mark around 10 degrees counterclockwise from the keyway on this keyboard. Photograph courtesy of Jeff Smith

  • On practically all Chevrolets from 1969 until at least the late 1970s, as well as on some even later engines, this is the most frequent small-block balancer timing mark/keyway offset. There’s a timing mark around 10 degrees counterclockwise from the keyway on this one. Jeff Smith provided the image.

It’s possible that you have a newer engine and timing tab, but that you have replaced the standard balancer from 1968 or older. After that, you may either set the balancer for actual TDC based on your current timing tab or purchase an aftermarket adjustable timing tab and balancer degreeing tape to make the adjustment yourself. If you go that far, you might want to consider a TDC stop in the form of a spark plug to permanently establish accurate TDC. (For further detail, see “How to Identify True TDC.”) Is there a pause in the timing chain?

The dots on the cam sprocket and cam sprocket must be completely aligned at No.

If they do not, the timing set has been implemented improperly or is malfunctioning.

On a stocker, on the other hand, it’s more than probable that the chain or sprocket is just falling apart.

Checks for Old Chevy V8 “Cranks, No Start” Condition

  • Possibly you have a newer engine and timing tab, but you have reinstalled the balancer that was originally fitted in 1968 and older models? After that, you may either set the balancer for actual TDC depending on your current timing tab or purchase an aftermarket adjustable timing tab and balancer degreeing tape to make the job easier. For those that go that far, consider using a TDC stop in the form of a spark plug to permanently establish accurate TDC. (For additional detail, see “How to Identify True TDC”). Is there a pause in the timer? If you have exhausted all other options, you can remove the harmonic balancer and front cover to inspect the timing chain underneath. If you want to fire No. 1 cylinder at TDC, the dots on the cam sprocket and cam sprocket must line up exactly. Otherwise, the timing set has been placed erroneously or is not functioning properly. With aftermarket multikey timing sets, incorrect installation occurs more frequently than we’d like to admit. If you’re looking at an idler, the chain or sprocket is most likely just disappearing. The nylon-tooth cam sprocket was used in many early General Motors passenger-car cam sprockets, believe it or not.

Sources

It’s possible that you have a later engine and timing tab, but that you have replaced the standard balancer from 1968 and earlier. If you have an existing timing tab, you may either check the balancer for accurate TDC or purchase an aftermarket adjustable timing tab and balancer degreeing tape. If you go that far, you might want to consider a TDC stop in the form of a spark plug to finally nail down real TDC. (For further details, see “Find True TDC.”) Is there a break in the timing chain? To examine the timing chain, remove the harmonic balancer and front cover if you have tried all other options.

1 cylinder, TDC firing, for the engine to run properly.

When it comes to aftermarket multikey timing sets, we have to acknowledge that incorrect installation happens more often than we would like to admit.

The nylon-tooth cam sprocket was used in several early General Motors passenger-car cam sprockets (believe it or not).

My Engine Will Not Start Up and Run

With 90000 miles on it, a 2003 Tahoe 5.3 Flex fuel. It did not start 2 months ago; it was diagnosed as a fuel pump failure; after replacing it with an Airtex, vehicle operated for a couple of weeks before failing to start again. There is no fuel pressure at the intake. I replaced the gasoline pump with a General Motors pump, and the car started and ran great for a couple of weeks. Then, while driving around, I shut the car off and it would not start again. With the key in the ignition, I wiggled the fuel pump relay until I obtained gasoline pressure and the engine started.

  1. For a few days, everything worked perfectly, but suddenly the no start situation returned.
  2. I was informed on another response site to replace the ignition switch, which I did, and the car ran great for a few days until it stopped starting.
  3. The following is what occurs when the no start condition occurs.
  4. If the gasoline gauge illuminates when I turn the key on, the car will start right away, and when it is running, it is flawless, never skipping a beat, and there are no check engine lights or anything of the kind.
  5. The fuel pump will not turn on.

The thought of this is driving me insane. Please let me know if you are able to assist. ADVERTISING SPONSORED LINK It will be at 11:51 a.m. on Tuesday, May 4, 2021. (Merged)

Intermittent hard crank/no start problem (Not Passlock)

Thank you to everyone for your continuous assistance and guidance. When I’m in the crank-no-start mode, the check engine light is illuminated. I’m not checking anything since the car fails on a regular basis while I’m driving and only starts after waiting 15 minutes, and because I’m not qualified to perform some of the electrical tests that have been advised. Again this morning, the same cycle was followed: a brief 5 minute drive, 45 minutes have elapsed, then crank-no start (check engine light illuminated), then 15 minutes of rest, and it begins to run.

In other words, I’m making educated guesses based on everything from my long list of repairs in my first post to my most recent attempt with the ignition switch.

Even though it turned out to be superfluous, the ignition switch had a high potential of being successful as was indicated earlier in the article.

04 colorado cranks but wont start

Same issue here (2011 3.5, in case it makes a difference), unplugged the battery and it would operate for a short period of time. It continued to deteriorate. I changed a number of sensors, including the TPS, and then the entire throttle body. I came upon a discussion thread concerning an anti-theft technology. Unless it was really cold (0 -10 degrees) in the mornings, this method has worked for the previous 120 days. 1. Keep the driver’s door open, 2. place the key in the ignition (but do not turn it on), and wait for the open door chime to sound four or more times, 3.

  • (Do not attempt to begin) 4) Wait for the dash lights (including the seat belt and other system lights) to go off.
  • With a handful of exceptions, my 2011 Colorado has started every day of the Ohio winter, save for one (then just a few minutes, it eventually started).
  • In the anti-theft security system, it appears, and there are a couple of suggestions to cut a certain wire, but I’m not too keen on that method.
  • They connect a scan code reader, but nothing appears on the screen.

99 Tahoe- Cranks, NO Start! HELP

I have a 1999 Chevrolet Tahoe with a 5.7-liter engine and four-wheel drive that will crank but will not start. Ok. As a result, the sequence of events 1) I was having trouble starting my car on occasion. I was taken to the shop, where it was discovered that I had two faulty injectors. As a result, the injectors were changed. I was behind the wheel of the vehicle for more than a week with no issues. 2) However, when I returned from the mechanic, I found that the check engine light was illuminated.

Because I’ve had my truck for a year and have no idea when the last time they were done, despite the fact that my truck has 243,000 miles on it!

It turns over but won’t start!

I was devastated! Please, for the love of God, someone come to my aid! I’m not even sure where to go from here. Alternatively, how to correct it! This is the printout from the GoodYearPrintout of the code from Autozone website. My Hoe, my Hoe!

Part 1 -How to Test the GM Ignition Control Module (1995-2005)

The 13th of April, 2009 Date last updated: December 26, 2021 Contributed by:Abraham Torres-Arredondo Article ID:266 This article is about This is one of the most straightforward GM ignition control modules to examine. This article will walk you through the whole process of diagnosing and troubleshooting a faulty ignition control module and ignition coil, from beginning to end. Assume that your vehicle is cranking but not starting due to a NO-SPARK condition before doing the ignition control module (ICM) and ignition coil tests described in this article.

Now, if you need to test a misfire situation, or if you need to test the spark plug wires, or if you need to test the distributor cap on this sort of General Motors ignition system, go to this link: How To Determine If There Is A Misfire / No-Spark No-Start Situation GM Distributor Ignition System for 4.3L, 5.0L, and 5.7L Engines (1996-2004).

  • The 13th of April, 2009. December 26, 2021 is the most recent update. By:Abraham Torres-Arredondo & Associates Identifier: 266 this article The ignition control module in this vehicle is one of the most straightforward to examine and test. You will be guided step by step through the whole diagnostic and troubleshooting process for a faulty ignition control module and ignition coil in this article. It is assumed that your car is cranking but not starting owing to a NO-SPARK state for the purposes of the ICM and ignition coil tests in this article. This article will not assist you if your General Motors automobile or truck starts and operates properly. You may now go to this link if you need to check for a misfire problem, or if you need to check for spark plug wires or distributor caps on this particular type of GM ignition system: A Misfire or No-Spark No-Start Condition Is Tested In This Way GM Distribution Ignition System for the 4.3L, 5.0L, and 5.7L engines (1996-2004). The following lesson may be of assistance to you because there are so many reasons that might cause your car to not start (such as a broken fuel pump, among other things).

NOTE:The following circuit diagram of the ignition system may be of assistance: Diagram of the ignition system for a Chevrolet/GMC pickup and SUV from 1996 to 1999. I’ve included a list of additional lessons at the conclusion of this tutorial that will assist you in diagnosing a cranks but does not start situation (in the event that the problem is not linked to the ignition system). In Spanish, you may find this instruction at: Cómo Probar El Módulo De Encendido General Motors 4.3L, 5.0L, 5.7L (1995-2005).

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Symptoms Of A Bad Ignition Module And Ignition Coil

In most cases, when the ignition control module (ICM) or the ignition coil fails, your GM vehicle or truck will crank but will not start. To be more specific, the ignition coil will not ignite. To make sure that the ignition coil is not sparking, you must connect a spark tester directly to the ignition coil’s tower and crank the engine. This must be done before proceeding with the rest of the test methods in this tutorial, for this reason. This is a very simple test, however it must be carried out with the aid of a spark tester.

TEST 4: Spark Test At Ignition Coil Tower ((This test is part of the tutorial:How To Test A Misfire / No Spark-No Start Condition (4.3L, 5.0L, 5.7L 96-04)).

In this situation, your car will start and operate the most of the time, but it will fail to do so on rare occasions.

What Tools Do I Need?

You don’t need a lot of equipment; in fact, you don’t even need a scan tool (although having a scan tool is helpful, but not necessary for this post)!

Here is what you will require in order to make full use of the information included in this article:

  1. A multimeter (don’t have a digital multimeter? Need to purchase one? Click here to see my recommendations: Buying A Digital Multimeter For Automotive Diagnostic Testing)
  2. An LED light. To see a picture of this tool go here: Abe’s LED Light
  3. A 12 Volt test light
  4. A aid to crank the engine
  5. s A wire piercing probe. This tool is really beneficial in terms of saving time. If you need to view what this tool looks like, click here: Wire Piercing Probe

As you can see/read, they are just fundamental tools; there is nothing elaborate, ostentatious, or EXPENSIVE about them.

Basic Operating Theory

Listed below is some background information that will assist you in diagnosing the ignition control module (ICM) or the ignition coil. In a nutshell, when you turn the key and start the engine, you are doing the following:

  1. Power in the form of 12 Volts is sent to several components, including the crankshaft position (CKP) sensor, the ignition control module (ICM), and the ignition coil. The crankshaft position (CKP) sensor begins to generate its own CKP signal, which it then delivers to the powertrain control module (PCM).
  • With an LED or an oscilloscope, the crankshaft position sensor may be observed to be a Hall Effect type sensor, which provides a digital (ON/OFF) signal that can be viewed with a crankshaft position sensor. It creates a digital square waveform when viewed on an oscilloscope.

As soon as the PCM receives the crank signal (together with the other sensor input signals), it begins to do a little song and dance before sending a signal to the ignition control module (ICM), which is referred to as theIC signal (IC=Ignition Control). With thisIC signal, the ignition module begins to engage the ignition coil, which results in the ignition coil sparking with aSwitching signal for the first time.

  • In fact, as you’re undoubtedly well aware, theSwitching signalis just a phrase that refers to the switching ‘ON and OFF’ of thePrimary Current’s route to Ground (thePrimary Currentrefers to the 12 Volts provided to the ignition coil).

The engine will begin to run if everything is in excellent functioning order. Important to understand is that the PCM, through the ignition control module, regulates the generation of spark from the start (cranking) and throughout the whole engine’s operating range’ (ICM). The very amazing thing about this sort of ignition system is that all of these signals (the IC signal as well as the Switching signal) can be verified with a few basic instruments, making it extremely easy to diagnose any problems.

Where To Buy The ICM And Ignition Coil And Save

To assist you in your comparative shopping for the factory original ignition control module and ignition coil, the following resources will be of assistance: Not sure if the ignition system components listed above are compatible with your specific General Motors vehicle? But don’t worry, as soon as you get at the site, they’ll check to see whether they fit and, if they don’t, they’ll locate you the appropriate ones.

Ignition Control Module (ICM) Circuit Descriptions

The ignition control module (ICM) has four wires flowing out of it, which are connected together. The following sections provide detailed descriptions of what each circuit accomplishes. Each circuit is designated by a letter, which corresponds to the letter that can be found on the connection of the ignition module’s connector. The circuit diagram for the ignition system shown below may be of assistance: Diagram of the ignition system for a Chevrolet/GMC pickup and SUV from 1996 to 1999.

Ignition Coil Circuit Descriptions

The ignition coil on your automobile or truck may or may not have three wires coming out of it, depending on the model. It makes no difference if it does or does not; the information contained in this test article remains valid. The following sections provide detailed descriptions of what each circuit accomplishes. It is necessary to identify each circuit by a letter, which corresponds to the letter that is found on the connection for the ignition coil.

  • When installed, the tachometer in the instrument cluster will receive an electrical signal from the tachometer.
  • SignalCircuit for switching signals. The wiring harness (circuit) for this device emanates from the ignition module.

A SignalCircuit for Switching Signals The wiring harness (circuit) is connected to the ignition module.

Ignition System Diagnostic Manual Download

In order to have access to a wiring diagram, the pin-outs for the ignition component connector pins, and the full testing method in one location, you might consider purchasing one of the following diagnostic guides in downloadable PDF format: Full-Size Pickups from the Chevrolet/GMC C/K Series:

Engines: 4.3L, 5.0L, 5.7L, 7.4L

$3.99 US dollars It contains all of the information you require to troubleshoot a misfire or a no-start issue (caused by the ignition coil, the ignition module, or the crankshaft position sensor). The following items are included in the diagnostic manual:

  • Dollars: $3.99 Detailed information on diagnosing and correcting a misfire or a no-start condition (caused by the ignition coil, the ignition module, or the crankshaft position sensor). The following items are included in the diagnostic manual.

There are no restrictions on printing the graphics in the diagnostic handbook! This applies to:

  • The 1996 Chevrolet C1500, C2500, and C3500 Pickup, the 1996 Chevrolet K1500, K2500, and the 1996 Chevrolet K3500 Pickup are all available, as well as the 1996 GMC C1500, C2500, and C3500 Pickup, as well as the 1996 GMC K1500, K2500, and K3500 Pickup.
Engines: 4.3L, 5.0L, 5.7L, 7.4L

$3.99 US dollars It contains all of the information you require to troubleshoot a misfire or a no-start issue (caused by the ignition coil, the ignition module, or the crankshaft position sensor). The following items are included in the diagnostic manual:

  • Dollars: $3.99 Detailed information on diagnosing and correcting a misfire or a no-start condition (caused by the ignition coil, the ignition module, or the crankshaft position sensor). The following items are included in the diagnostic manual.

$3.99 US Dollars Here is all you need to know about diagnosing a misfire or a no-start problem (caused by the ignition coil, the ignition module, or the crankshaft position sensor). The following are included in the diagnostic manual:

  • Pickups from 1997 Chevrolet include the C1500, C2500, and C3500, as well as the K1500, K2500, and K3500. Pickups from 1997 GMC include the C1500, C2500, and C3500 and the K1500, K2500, and K3500, as well as the Chevrolet K1500, K2500, and K3500, as well as the Chevrolet K1500, K2500, and K3500.
Engines: 4.3L, 5.0L, 5.7L, 7.4L

Pickups from 1997 Chevrolet include the C1500, C2500, and C3500, as well as the K1500, K2500, and K3500, and pickups from 1997 GMC include the C1500, C2500, and C3500.

  • Detailed wiring schematics
  • Component pinouts
  • Connector pinouts
  • Firing order diagrams Testing guidelines that are comprehensive and step-by-step

There are no restrictions on printing the graphics in the diagnostic handbook! This applies to:

  • 1998 Chevrolet C1500, C2500, C3500 Pickup
  • 1998 Chevrolet K1500, K2500, K3500 Pickup
  • 1998 GMC C1500, C2500, C3500 Pickup
  • 1998 GMC K1500, K2500, K3500 Pickup
  • 1998 GMC K1500, K2500, K3
Engines: 4.3L, 5.0L, 5.7L, 7.4L

$3.99 US dollars It contains all of the information you require to troubleshoot a misfire or a no-start issue (caused by the ignition coil, the ignition module, or the crankshaft position sensor). The following items are included in the diagnostic manual:

  • Detailed wiring schematics
  • Component pinouts
  • Connector pinouts
  • Firing order diagrams Testing guidelines that are comprehensive and step-by-step

There are no restrictions on printing the graphics in the diagnostic handbook! This applies to:

  • A 1999 Chevrolet Silverado, C1500, C2500, and C3500 pickup truck
  • A 1999 Chevrolet K1500, K2500, and K3500 pick-up truck
  • A 1999 GMC Sierra, C1500, C2500, and C3500 pickup truck
  • And a 1999 Ford F-150 pickup truck
Engines: 4.3L, 5.7L, 7.4L

$3.99 US dollars It contains all of the information you require to troubleshoot a misfire or a no-start issue (caused by the ignition coil, the ignition module, or the crankshaft position sensor). The following items are included in the diagnostic manual:

  • Detailed wiring schematics
  • Component pinouts
  • Connector pinouts
  • Firing order diagrams Testing guidelines that are comprehensive and step-by-step

Detailed wiring schematics; component pinouts; connector pinouts; firing sequences directions for doing the tests in detail;

  • 2000 Chevrolet Silverado, C2500, C3500 Pickup
  • 2000 Chevrolet K1500, K2500, K3500 Pickup
  • 2000 GMC Sierra, C2500, C3500 Pickup
  • 2000 GMC K1500, K2500, K3500 Pickup
  • 2000 GMC K1500, K2500, K3500

2000 Chevrolet Silverado, C2500, and C3500 Pickup; 2000 Chevrolet K1500, K2500, and K3500 Pickup; 2000 GMC Sierra, C2500, and C3500 Pickup; 2000 GMC K1500, K2500, and K3500 Pickup; 2000 GMC K1500, K2500, and K3500 Pickup; 2000 GMC K1500, K2500, and K3500 Pickup; 2000 GMC K1500, K

Engines: 4.3L, 5.0L, 5.7L, 7.4L

$3.99 US dollars It contains all of the information you require to troubleshoot a misfire or a no-start issue (caused by the ignition coil, the ignition module, or the crankshaft position sensor). The following items are included in the diagnostic manual:

  • Wiring schematics
  • Component pinouts
  • Connector pinouts
  • Ignition system component part numbers
  • Firing order
  • And other related information. Testing guidelines that are comprehensive and step-by-step

There are no restrictions on printing the graphics in the diagnostic handbook! This applies to:

  • Chevrolet Express Van (from 1996 to 1999)
  • GMC Savana Van (from 1996 to 1999)
Engines: 4.3L, 5.0L, 5.7L, 7.4L

$3.99 US dollars It contains all of the information you require to troubleshoot a misfire or a no-start issue (caused by the ignition coil, the ignition module, or the crankshaft position sensor). The following items are included in the diagnostic manual:

  • Wiring schematics
  • Component pinouts
  • Connector pinouts
  • Ignition system component part numbers
  • Firing order
  • And other related information. Testing guidelines that are comprehensive and step-by-step

There are no restrictions on printing the graphics in the diagnostic handbook! This applies to:

  • 2000 Chevrolet Express Van
  • 2000 GMC Savana Van
  • 2000 Ford Transit Van

A 2000 Chevrolet Express Van and a 2000 GMC Savana Van are available for purchase.

Engines: 5.7L

$3.99 US dollars It contains all of the information you require to troubleshoot a misfire or a no-start issue (caused by the ignition coil, the ignition module, or the crankshaft position sensor).

The following items are included in the diagnostic manual:

  • Dollars: $3.99 Detailed information on diagnosing and correcting a misfire or a no-start condition (caused by the ignition coil, the ignition module, or the crankshaft position sensor). The following items are included in the diagnostic manual.

There are no restrictions on printing the graphics in the diagnostic handbook! This applies to:

  • Printer-friendly graphics can be found in the diagnostic handbook! Affects those who are

Suburbans from Chevrolet and GMC:

Engines: 5.7L, 7.4L

$3.99 US dollars It contains all of the information you require to troubleshoot a misfire or a no-start issue (caused by the ignition coil, the ignition module, or the crankshaft position sensor). The following items are included in the diagnostic manual:

  • Circuit schematic
  • Component pinouts
  • Connector pinouts
  • Ignition system component part numbers
  • Firing order
  • Comprehensive step-by-step testing instructions

There are no restrictions on printing the graphics in the diagnostic handbook! This applies to:

  • Chevrolet Suburban (4×2 and 4×4) from 1996 to 1999
  • GMC Suburban (4×2 and 4×4) from 1996 to 1999

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