warauto

Hello everyone I have a s13 sr20det in a s14 it has been running for many years but since a year or so the quality of the motor has begun to fade.

The modifications list is as follows.

1. S13 sr20det late model with fins.
2. Custom turbo intake pipe.
3.Front mount intercooler.
4. Walbro 255 fuel pump.
5. New 300zx fuel filter.
6. AFC 2.
7. 11 lbs of boost

The problem : A few days ago the car just started to randomly misfire, sounding like it was running on only 3 cylinders. It sounded like a subaru unevenly and roughly throttling. It did not have much power and refused to boost properly. I took it home checked all the coil packs...all were good. Popped the plugs and i found that cylinder 4 plug was all black, it was not wet but I just took that as a sign of fuel dumping. So I gapped a new set to 0.030 and put them in. The problem still persisted.

The fuel system- I decided to turn to the fuel system since the ignition system seemed to be working fine. I started by plugging off each injector wire. Cylinder 3 was made no change to the motor so I shut it down and gave it a couple taps and left it for a few and it started working...maybe it was clogged or something, I am not sure. Now it only misfires while driving and idles roughly, not as much as it did before but it still is. The cylinder 4 plug is black after only about 3 miles.

Compression test is as follows 1-145 2-143 3-140 4-150.

Need any input why the car is still misfiring, ohh and vacuum is good and i have no boost leaks.