Recently I got a CEL for misfire in cylinders 1 through 4, and notice a small amount of power loss around 3k rpm.

I checked spark plugs, ignition wires, dist cap seems fine. I went to check my fuel injectors and one was cracked so I replaced it.

However, the car still sputters in 1st gear around 3100rpm and sputters in 2nd gear around 3500 rpm.

After passing those RPMs however, the car will run fine. I have noticed that accelerating slowly but gradually seems to make the problem worse. When I WOT, no problem at all.

Did a compression check, compression was around 180 on all cylinders. Did a fuel pressure test when idling and running, and the pressure seemed fine, until i turned the car off... it went from 35psi to 0 in about 10 minutes. I couldnt find a leak anywhere. Also, when I was trying to run more tests for fuel pressure, Im guessing the gauge stopped working because I had the car on and running fine and the gauge was reading 0psi lol.

I have access to an OBDII scanner, and Ive been getting a positive Short Term Fuel Trim correction of about 46.9! Long term fuel trim is at -0.8. Huge difference. Also before this CEL I had a CEL for lean condition, but after replacing my fuel filter it went away.

Im guessing its the fuel pump causing the misfires. A friend of mine believes its something related to the inside of the distributor. Any help is appreciated.

 

Try and reset the ecu either unplug the ecu from the harness for a few mins or pull the ecu fuse from the engine bay fuse box. or scan it with a obd scanner and clear the code. Are you sure the rest of the injectors are still good? i dont think its your fuel pump.