I have a 1997 Vortec 5.7L and it's throwing the P1345 code.I know that the usual suspect is that the timing is off and I need to take itto a shop and have them adjust the distributor with a scan tool.

But before I do that I want to make sure that is my problem.The truck starts/idles fine. However, sometimes when I try to accelerate, the engine seems to fall on its face and sometimes even dies. Sometimes it accelerates smoothly. Every once in a while it will start surging violently when idling in gear at a stop light. It also pings really bad at certainRPM/throttle position. Does this sound like the effects of incorrect distributor position?

 

Anyone?

 

could be a worn distributor gear. remove the dist cap, grasp the rotor and see how much play it has.

 

Thanks. That's exactly what I thought too. I replaced the distributor and it's acting the same.

 

is this a high mileage engine? Maybe the timing chain is stretched

 

Actually it is. About 240,000 miles on the engine.

Would a stretched timing chain cause the P1345 code?

 

yep. Its a possibility.


there is a test you can do to check this without removing the timing cover. but since there is only one timing mark on the crank, you would have to degree the crank.


It involves putting the crank a tdc, turning the crank backwards until you see dist movement. then record the amount the crank has move. I think 8* is the limit.

 

I will try that this weekend. Thank you.

 

I took the truck to a shop and they are saying the ignition timing and the timing chain are fine.

The issue is that the crankshaft position sensor is soaked with oil. I haven't yet replaced the sensor to see if that fixes the problem.

 

makes no sense to me. they are positioned through an access hole in the engine that would normally get oil throw off. That's why they have a o-ring; to stop oil leaks.


If you think the sensor is bad, definitely swap it out.