Dad’s car is giving me fits. Starts fine, idles for a few minutes, then starts backfiring, rough idling and stalls out. If you run it up through the RPMs, it begins to backfire around 3000 RPM. It does the same rough engine noise at that rpm. I have swapped the AFM, FPR, and anything else I could think of. There is a confirmed vacuum leak in the throttle area but not enough to make a difference. The intake manifold also has a gasket leak under vacuum but I can’t imagine that it would be enough to cause this problem. The most worrisome part is that I hear a rattle in the valvetrain and a knock in one of the center pistons however I cannot determine if this is the cause or a symptom as it only does it when the problem arises. I did a valve adjustment recently per the Bentley manual. Any ideas?
Backfire, engine knock, stall and code 1222
bedmonds
#4
Update: was not the coil. Not ready to close the book but so far so good. Pulled the intake and for some unknown reason there were two gaskets on cylinder 6. Redid the valve job but they were good so I don’t think that was it. Fired it up and voila.