1997 C3500 7.4L P1345 code

[Mark_Pacheco]

Engine rebuilt by shop 700 miles ago. Replaced MAF sensor, downstream O2 sensors, now getting P1345 code. Engine clicks when cold, hard to start when at operating temp and blows black smoke when it finally does start. Runs fine when cold, struggles on acceleration when at operating temp. Suggestions?

[777stickman]

P1345=CKP/CMP correlation. This means the crank position sensor and the cam position sensor are out of phase. Most likely cause is the dist is one tooth off on either side. Also need a high end scanner capable of getting into "cam retard" or "cam offset" mode to set timing (0 +/- 2 degrees @ 1000 rpm).

[Mark_Pacheco]

Makes sense to me. The only thing that I wonder about is why the error wouldn't show up prior to 700 miles of being driven. Also, I had two rich fuel mix codes show up prior to this error. I figure if the cam is off by a tooth, it should have registered before, or at least, when the rich fuel error did. Or am I misunderstanding how these newer engines provide codes?

Thanks!

[Jeremy-WI]

Originally Posted by markcpacheco

Makes sense to me. The only thing that I wonder about is why the error wouldn't show up prior to 700 miles of being driven. Also, I had two rich fuel mix codes show up prior to this error. I figure if the cam is off by a tooth, it should have registered before, or at least, when the rich fuel error did. Or am I misunderstanding how these newer engines provide codes?

Thanks!

It could be the effect of the distributor not being set perfect after the rebuild and the wear on new parts. I would consider the rich codes just another side affect of the distributor not being right. There have been cases of extreme distributor gear wear but I don't think any of those had less than 50k miles

[777stickman]

Here are some more things that can cause this code.

1. A loose CMP sensor in the dist.
2. Excessive timing chain play.
3. Loose rotor on the dist shaft.
4. Loose or missing dist hold down bolt.

Need the rich DTC codes to try and help with that.