96 zr2 4.3 sputtering acceleration and kicks a little on highway.

[joshgaines]

About a year ago my truck sputtered and broke down with check engine light flashing. I replace fuel filter, pump, cleaned out gas tank, new plugs and wires. Got it running good. But check engine light was still on. I think the code was p0340 (cylinder 1 misfire, still has same code today). I drove it as is for 6 months like that, never had a problem except with accelerating it would ACT like it wants to die but never would, i would describe it as hesitating but i just let off gas and mash it again and varoom it takes off. When i would get on the highway at 70mph, it would surge/kick/miss really fast and not do it every again, or do it every 5 miles or so. This problem is a hit and miss, its not consistant. I changed my camshaft posistion sensor yesterday and nothing. I looked at my cap and rotor, the cap had yellow crystals on the contacts and what looked to be where it has melted(for lack of a better word) on one sideof the contacts. And the rotor contact looked burned and melted( its not melted DOWN more of expanded i would say). But before it broke down i never had a problem. Also this last winter it got down to about 20* or so and i went to reverse and she died. The check engine light went off for the first time ever(started right back up) and didn't come back on for a few days. I have the CSFI injectors. I have read i need to replace with MFI and problem solved? No vacuum leaks, no gas leaks, everything looks and sounds great. Just the mystery mentioned. Also i have the horizontal dis. numbered 2, 4, 6, c on pasanger side and 3, 1, 5 on driver side. I have it wired as read on passanger, and 1 being at the front of motor running to 1 marked on dis. and 3 being middle cylinder going to 3 marked on dis. Is the firing order correct? Any input on this would be greatly apperciated. Im about to just bash my head in on this. I have worked on this problem for a year, talked to a ton of people, looked all over the net. Ran tests, replaced parts. And i still have the proplem. Just about every sensor i can imagine has been replaced. The cap and rotor looked new other than what i mentioned. I checked the TDC when i pulled the cam sensor and it was right on. So if you have any questions, ask away. If i missed anything let me know. Please help. THanks for your time, Josh

Ok i went back in some of my old notes and p0340 was for CPS bank 1 circuit malfunction, which i replaced the CPS. What else would cause that code other than a short in the wiring? I will check the wires tomorrow morning. Thanks again, i know this is a difficult problem to troubleshoot but any input helps.

Ok i also found this on AF website "P0340 - Camshaft Position Sensor A Circuit (Bank 1 or single sensor)"...

[blazes9395]

What do you mean check TDC? Did you get a scanner on there and check for camshaft/crankshaft sync? You could have a worn distributor gear. Did you replace the intake gaskets, or anything that required the removal of the distributor shaft?

[joshgaines]

Top dead center, Never removed intake or dis., me or prior owner. I haven't had a scanner on ther while running. Just at autozone to check codes. The only code it has ever gave me was p0340.

[joshgaines]

Well i guess i fixed it when i replaced the CPS. Today on the way to work, the check engine light went off, and no more kicks or sputtering. I disconected the battery while i changed the CPS, i figured that would have reset everything. Guess not. Im guessing after it ran a full cycle it reset. Not sure how it works exactly on this truck.