Half cylinders firing on startup? Please help

CWBenjamin

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Hello.
I replaced my head gaskets and timing chains and guides.
In doing so noticed my MAP sensor was damaged, so I replaced that a couple days later.
After I replaced that, I immediately got 2 engine codes:

p0340 - No camshaft reference signal at pCM
P1391 - Loss of crankshaft crank

It didnt seem to run different than it has been lately, which is a little rough honestly and feels like it has a misfire or something causing an uneven vibration intermittently...

Last night I replaced the camshaft sensor and after that, it started up but seemed like it was only running on a few cylinders... It seemed to idle okay, but when i gave it gas it chugged and struggled.
I turned the key off and started it again, it seemed to take a moment for the started to start it up, but this time it seemed to run fine... then this morning when i started it, started up quicker but again was only seeming to fire a few cylinders and struggled to move.

Any ideas? TIA

Could a bad starter cause only half the cylinders to fire up and run or does anyone have any ideas?
 
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Ksat

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You need to check the cam sensor for power, ground and output signal. An oscilloscope is the best way to do it, but a capable multimeter might work in a pinch.

I don't see how a bad starter would cause the issue u described.
 

CWBenjamin

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You need to check the cam sensor for power, ground and output signal. An oscilloscope is the best way to do it, but a capable multimeter might work in a pinch.

I don't see how a bad starter would cause the issue u described.

Do you know if the alternator plug being damaged could affect the camshaft sensor? (The small plug with 2 wires on top rear of the alternator) The plug on the back of my alternator got damaged when i had some work done. It seems to hold on still but not as good as it should.
 

Ksat

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Do you know if the alternator plug being damaged could affect the camshaft sensor?

I doubt the problems are related.
 

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