Crank no start?

SOBRYANT63

MEMBER
2003 CHEVROLET SILVERADO
0.5L
V8
2WD
300,000 MILES

Replaced camshaft position sensor, tried to start truck but would crank and not start. Performed a relearn procedure truck started right up. Check engine light off, no codes. A couple of hours later I had to run some errands, truck cranks, no start. Put code reader on, 10 codes. I unplugged the camshaft position sensor, checked wires and plugged it back in. The truck started right up. Now the only way my truck will start is if I unplug the sensor, wait a minute or two and plug it back in. I'm going crazy with this. Any help would be greatly appreciated.

Friday, April 7th, 2023 AT 8:14 AM

5 Replies

JACOBANDNICKOLAS

MECHANIC
110,176 POSTS

Hi,

That sounds like it would drive me crazy as well. LOL Is the connector and connector pins in good condition, free of corrosion or damage? It sounds like you make the connection when you remove it and replace it, and it is lost if the connector isn't touched. Do me a favor. When you try starting it and it won't start, before disconnecting it, wiggle the wiring to the connector to see if that makes any difference.

Also, I'm almost afraid to ask for these because there are so many, but let me know what the ten codes were. I want to see if anything is related that could be causing the problem.

Let me know.

Take care and Happy Easter,

Joe

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Friday, April 7th, 2023 AT 11:00 PM

SOBRYANT63

MEMBER
3 POSTS

I tried wiggling, doesn't work. Codes are p1133, p1516, p031, p0171, p0332, p0342, p0894.
By the way I've already replaced o2 sensors crankshaft position sensor mass air flow sensor.
I'm starting to lean towards Demon Possession.

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Saturday, April 8th, 2023 AT 9:25 AM

JACOBANDNICKOLAS

MECHANIC
110,176 POSTS

Hi,

Demon Possession... LOL I needed that laugh. However, considering tomorrow is Easter, we have the odds in our favor.

The codes are all over the place. Knock sensor, oxygen sensor, transmission, and so on.

Here is what I want you to do. When it won't start, before disconnecting and reconnecting the cam sensor, check to see what we lost. It will either be fuel or spark. See if it starts using starting fluid and then stalls. If it does, we need to focus on the fuel system. If there is no change, we need to check for spark at the plugs.

Here is a link that explains how that is done:

https://www.2carpros.com/articles/how-to-check-for-ignition-spark

Just for curiosity, will it start with the sensor disconnected? Also, I need confirmation on the engine size. There are multiple V8s it could be.

Let me know.

Take care and Happy Easter,

Joe

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Saturday, April 8th, 2023 AT 7:22 PM

SOBRYANT63

MEMBER
3 POSTS

Well, starter fluid didn't work. Spark doesn't seem to be a problem. Here's the weird thing, I pulled the new sensor out and put the old one back in. Truck started right up. Runs like crap but at least it starts. By the way it's a 5.3L.

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Wednesday, April 12th, 2023 AT 12:49 AM

JACOBANDNICKOLAS

MECHANIC
110,176 POSTS

What codes does it throw when it is running like this? I have a feeling the new sensor was bad. However, if you have ignition spark and fuel, it should run unless compression is too low or the timing is off.

So, is it possible for you to record it cranking and running and upload it for me to hear? Also, it may be a good idea to perform a compression test. If the engine has 300K, the compression can be weak.

Let me know.

Joe

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Wednesday, April 12th, 2023 AT 7:14 PM