I've tried searching to my wits end. I've recently replaced cap button plugs wires fuel filter and sea foam and Lucas fuel treatment. I checked fuel pressure at idle is around 58 lb. It has a noticable miss to it under certain conditions of partial throttle only. I am wondering if if p1345 is causing my p0300 and miss or what. And what should I change or do to try and trouble shoot more. If already checked the basics. Vaccum spark and fuel pressure. What next in my journey. Any help would be greatly appreciated. Thanks in advance.

Jon.

 

What are you driving and have you read these posts?
P1345 Explained
The dreaded P0300 CAUTION LONG POST

 

yea i read the po300 one but never did find the 1345 one. its a 2001 4.3 4x4 blazer. never been touched untill after these codes started.

 

But you clicked on the hyperlick I created and read the P1345 post now, right?

 

Yea I did and now I rechecked the dizzy cap and button. Could it possibly be a bad crank sensor. And I only have a code reader no scanner. Or ignition modual.

 

i got my buddies determinator scanner today from him and done some digging into the blazer. i found that when i went to check the cam sensor i got no data on all the cam sensor readings. but i did have a good timing at around 6-13*. my question now is it apperars to be the cam sensor since im not getting rpm readings or anything from it, but would my timing still advance and be that close with the cam sensor being bad?

 

ok one more question. im not sure what fixed it but the missfire is now gone. i replaced the distrubuter ignition module and coil. my next question is a simple one. i believe i got the distubuter in one tooth clock wise. im still throwing the p1345 code which could be cause if the dizzy is one tooth off. it runs good but when sitting for a little while it is slightly difficult to start. it cranks about 6-10 seconds before starting when it used to start in about a second. does this sound like a dizzy out of time problem too.

 

I doubt your distributor is one tooth off.

Did you ever do anything with the CMP sensor (camshaft position)? Did you follow the diagnostic steps in the P1345 link provided by Rich?

 

Yes I did. I replaced the distrubuter with a new one. Which had a new cam sensor. Which is why I think it may be one tooth off.

 

Did you get the CMP/CKP correlation relearn done? This is commonly referred to as the CASE relearn or Crankshaft Variation Learn Procedure and should be done whenever the CKP, CMP, or PCM is replaced. Not having the proper CMP/CKP correlation value in the PCM can set the P1345 code.