Didn't see anything on here about this, so thought I'd add something in case someone else had the same problem.

I have a '97 Silverado with the 5.7 and 180K miles. A while ago the Check Engine light came on and scanned to a P1345 code, which is an indication that the synchronization between the Crankshaft and Camshaft is off. There are sensors for both - the crankshaft position sensor is located up front (somewhere, I never did have to find that one) - while the camshaft sensor is located in the distributor.

So, after some research online it sounded like there were numerous things that could be wrong, including a distributor off a tooth, a distributor not quite timed right (like changing your timing on older engines, only now it changes the relationship between the cam and crank - from the sounds of it) and bad sensors.

With mine however, it turns out the distributor drive gear was getting worn out, which gave enough play that the cam sensor was reading too far off where the computer thought it should be, based on where the crank is positioned.

The answer was to swap out the drive gear, although I just swapped out the old distributor for a new one since I wanted a new rotor and cap anyway. Right after I replaced the distributor, the check engine light went out - no problem since.

Also, another symptom I had that was resolved, was that cruising around 40mph or so, it seemed as though there would be an occasional missed cylinder, just a skip. Anyway, seems to have fixed that as well, but was probably due to the distributor being old anyway.


Hope this helps someone.

 

Thanks for that bit of good info. Hopefully it will help someone in the future...

 

Cheers, hope it does too, and that I wrote it coherently - it made more sense in my head than I was able to express on paper.