Crank no start?

2004 CHEVROLET SILVERADO
180,000 MILES • 5.3L • V8 • 2WD • AUTOMATIC
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CURE4SALVATION
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So, I parked my truck the other day and went to leave again. It hasn't started again since. I replaced the crank sensor, fuel pump, and cam sensor. Turns over no fire replaced all coil packs checked all fuses relays all good. So could be the harness or PCM?
Apr 27, 2023 at 6:18 AM
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JACOBANDNICKOLAS
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Hi,

The first thing I need you to check is the ground for the ignition coils. The coils share a common ground, and they are known for failure. I have a feeling that is the issue.

If you follow the harness, you will find the ground wire (black wire) runs to the driver's side of the engine. It should be toward the front of the engine block. Check the connector and connection. The eyelet used to attach the wire to the block is likely ready to fall apart or is already broken.

If the ground is good, then check the dark pink wires at each coil to see if there is power with the key in the run position. Note that the power is supplied via injector fuses. I don't know if you may have missed that.

Pics 1 and 2 show the fuses and coil wiring. Pic 3 is the location of the ground wire I'm referring to.

Let me know what you find.

Take care,

joe

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Apr 27, 2023 at 1:38 PM
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CURE4SALVATION
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I will check power again but had power and harnessooks good truck ran fine then went to leave again has started since key you hear throttle plate open and all clicks under the hood fuel pressure good no fire on any cylinder.
Apr 28, 2023 at 8:36 AM
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CURE4SALVATION
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How can you test a crank sensor? Is it possible and cam all fuses good injectors fuses good?
Apr 28, 2023 at 8:37 AM
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CURE4SALVATION
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Thank you for your time and assistance greatly appreciated.
Apr 28, 2023 at 8:41 AM
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JACOBANDNICKOLAS
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Hi,

Were you able to locate the ground I mentioned? As far as the crank sensor is concerned, check to see if there is an RPM signal when cranking the engine. You need a live data scan tool to check it.

Let me know.

Joe
Apr 28, 2023 at 3:47 PM
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CURE4SALVATION
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Yes, I did turns out there were 2 faulty crank sensors just received ac Delco sensor and connector starts up. Crazy 2 new sensors no good from AutoZone. I do appreciate you taking the time out of your day to assist this matter.
May 2, 2023 at 4:32 AM
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JACOBANDNICKOLAS
  • ✓Experienced Mechanic
  • 110,240 POSTS
Hi,

Thank you for the update and you are very welcome. I have seen so many aftermarket parts that are faulty. Usually, I don't have that issue with AZ. However, we are importing so many inferior parts/components. I wish I had a nickel for each time I saw this problem.

Regardless, I'm glad to know it's running for you. Feel free to come back anytime in the future.

Take care of yourself,

Joe
May 2, 2023 at 12:21 PM
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