fishyboi4

Sorry to do this but I'm creating another misfire thread. Reason is because I need a little guidance from you guys. Anyways a little info on the car, I've owned it for about 1 year now, got it from my brother with it already having misfire issue. As it being my first manual I have misshift a couple of times at near redline. The codes came out being the common ones P1399, P0301, P0302, P0303, P0304 We have done the basic check up on the car as everybody suggested. He gave the car a valve job(kind of doubt that he did it right though, but it's just my self conscious of insecurity but he did follow the diy guideline and does know what he's doing most of the time). He bought new coil packs, took the fuel injector out for a inspection and it ran fine, replaced spark plug twice, once at 20k miles ago and then I just put some new NGK Iriduim in again the other day. Just the other day it only threw P1399 and P0302 so I swapped cylinder 2 coil pack with cylinder 3 but no difference it actually threw more codes at me. I ran a compression test and all cylinders ran around 235 psi, no low compression. So the question is what should I do next? I'm thinking about rerunning a compression/ wet compression test again(haven't done wet test yet). Should I run a leakdown test since my compression test came out good? Should I replace fuel injectors? what else could be the problem? thinking about swapping the catalytic converter to a test pipe and run cel fix to see if it may be cause from a faulty converter earlier on. What are you guys sugguestion? I'm about to go buy two techron fuel system cleaner and dump it in the gas tank to see if that does anything.

fishyboi4

alright so i just poured a 20 fl oz Techron in and car doesn't seem to be misfiring, not sure if its from the Techron or not but I just checked the the codes again after starting it with no misfire the codes were P0300, P0301, P0304 so I cleared it. Reran the compression test again and here's the result( ran each cylinder 3 time)


Cylinder 1
235
235
230


Cylinder 2
235
245
245

Cylinder 3
238
240
240

Cylinder 4
240
245
245


I reran Cylinder 1 again because it came out pretty low so I figure it might be because it was the first run, and then the codes came out to this.

Cylinder 1 rerun
240
240
245

I ran the compression test when my car was warm btw. and since the number came out okay should I do a wet compression test?

s2000maniac

It's the probably the fuel injectors.