I can't figure out why I'm getting this misfire for the life of me. When you first drive the car when cold and hit the gas the car runs like a brand new one. After it gets hot and you kick it it misfires has low power at full boost. When I would stay on the gas for about 3 or 4 seconds the Service Engine Soon light would flash and then it would stay solid. at first i was getting a P0303 and a P0305. Since messing with it it has calmed down to a P0305 everytime. I have changed the spark plug, wire, coil pack, and fuel injector. It only does this when Supercharger boosts. If i drive the car without ever needing boost it will not misfire. I did a compression check on the cylinder and it passed. I also had my Ignition Control Module tested and it checked good. So I honestly have no clue where to go from here? This problem kind of happened suddenly one day when i started up the car. When we hooked up the fuel pressure guage, the needle was erratic around 44psi If we dissconnected the vaccum on the regulator it steadied a little but needle still was very shakey, never steady.
This is a $400.00 AC/DELCO aftermarket fuel pump. Would like some feedback before this investment is purchased and then did nothing to rectify the problem.
I have access to all diagnostic tools that would be needed for any test suggestions.
Thankzs!
