PRD2BDF wrote:
Do you need me to man the phones?
Nice one Cody. Can you hear me now?
With the new PCM now logging codes, we could narrow it down a little better, but we were already looking at something goofy on #6 last week anyway. It's reporting random misfires on 4 and 6, as well as P1631 Theft Deterrent Start Enable Signal Not Correct, which I assume is due to the donor PCM not recognizing the VATS module, but the car starts and runs fine other than 4 and 6. #6 is fuel fouling. 2 and 4 plug wires were swapped, 4 and 6 still misfired. 6 and 3 plugs were swapped, 4 and 6 misfires remained. 1/4 and 2/5 coils were also swapped with no change.
Due to the fact that he has no fuel pressure gauge with him, I had him disconnect the vac line to the FPR to command higher mechanical pressure in the rail on the off chance it was low, no change. Last week he did a 'thumb comparison' compression check between 3 and 6, both felt the same as far as he could tell. Oil and coolant are not mixing, all fluids look normal.
During troubleshooting, he noted that when he disconnected the wire from the #6 coil terminal, the idle didn't change. When he disconnected the #4 wire from the coil, the idle seemed to actually IMPROVE a little. I asked him to confirm that in the morning and try to borrow a fuel pressure gauge at a local auto parts store first thing in the morning before they decide to tow the car home to Oregon from Bum-fuk freaking Wyoming.
Very odd stuff here, with serious undertones of doom that I'm not willing to accept yet. It hasn't slipped past me that 4 and 6 are adjacent cylinders, but Matt confirmed they are stock L32 head gaskets and heads, OEM from the factory. When he L32'd, he kept the block and heads intact, and only swapped in the cam.
This one is most definitely not your run-of-the-mill misfire issue, complicated by the fact that he has few tools to troubleshoot with in Laramie.
