Can vibrations trigger P0300 in a 3.8?
I put a replacement engine in my 97 firebird with a 5 speed. Ever since it always gets random misses.
Every possible thing has been tried wires, plugs, shield removal, fuel pressure, egr delete, injectors, coil packs, ICM .... EVERYTHING
It only seems to trigger it at elevated rpm or speeds, code for evap also present.
One odd thing is it's brakes they have always seemed harder to push then other f-bodies I have owned, but with vacuum line off p0300 will still come up as well as flash the check engine light.
Now I do feel a pulsing vibration in the transmission case, but could a possible missing balance shaft also cause this?
If I just drive car like a grandma and putt it around town and stay under 60mph and under 3000rpm it rarely will trigger p0300
This is also a smog issue for me as well so this needs to be taken care off. I have heard with a tech2 it can be used to shut off random miss reporting, but will that in turn fail in a smog check under self tests?
No crank relearn was ever done on the car.
Could the PCM be the culprit?
One other thing the car does at times is cranks and cranks before it will start, that has never been fixed.