I have a 1987 Pontiac Fiero 4cyl and it has been misfiring since I got it. It has a new O2 sensor, MAP sensor, Ignition Coils, spark plugs, spark plug wires, air filter. It is not a exhaust leak problem and the misfire is too big to be a vaccum leak in my opinion. It has a Direct Ignition System so it is not timing either. I've had suggestions of a sticky valve but I'm not so sure. Thanks for your input.
Notes: Spark plugs ARE gapped correctly.
I did a compression test and all cylinders were normal.
Notes: Spark plugs ARE gapped correctly.
I did a compression test and all cylinders were normal.