S14 SR20 Breaks up at high RPM.

[Slammed95S14]

Alright. So I tuned my car, the car ran awesome, and pulled real good. One night I was out driving and got on it in first slammed second, then after that it basically acted like it had bad plugs in it at high RPM. So I bought a set of Ngk Iridium 3764's gapped at .28 and it still does the same thing. The car drives fine until you hit about 4k. I'm doing about 12-13 lbs.

Things I think might be wrong,CoilsMAFPossibly CAS.

Has anyone had this problem? Any help is appreciated.

[s14tan]

it sounds like a MAF problem,My car did the same thing, I solved the problem by Cleaning the MAF with some MAF cleaner from Autozone (CRC MAF cleaner I believe) and I just reset the timing.after that the car ran like a champ. I think you should give it a shot, a can of CRC is about 4-5 bucks. and resetting the Timing doesn't really cost you anything but time.Let me know if it works out for you bro.

[Slammed95S14]

it sounds like a MAF problem,My car did the same thing, I solved the problem by Cleaning the MAF with some MAF cleaner from Autozone (CRC MAF cleaner I believe) and I just reset the timing.after that the car ran like a champ. I think you should give it a shot, a can of CRC is about 4-5 bucks. and resetting the Timing doesn't really cost you anything but time.Let me know if it works out for you bro.

Thanks alot man. That was going to be my first thing to try. It's the most inexpensive. The timing should be spot on, because I just set the timing at 12.5 degree's at idle when I tuned the car which was a couple weeks ago. Thanks alot for your input! I'll let you know what happens!

[overdosedave]

this might sound stupid but do u have a wideband to see what is goin on at those rpms?

[Slammed95S14]

this might sound stupid but do u have a wideband to see what is goin on at those rpms?

Yes. AEM Uego. The tune is not the problem.

[s14tan]

Did the MAF cleaner do the trick?

[the converted]

Your timing is a bit retarded (should be 15*). What are the a/f's when it starts to break up? Have you checked for a boost leak?

[Tulsa_S-13]

Have you checked for a boost leak?

That's exactly what I was thinking. I had the same problem upon installing my FMIC. Made a boost leak tester, fixed the problems, problem solved.

[Slammed95S14]

Did the MAF cleaner do the trick?

No the MAF cleaner didn't help. I made a leak tester and fixed alot of leaks but the car still does the same thing. I'm thinking it may be the MAF, but I don't have another to test it out with. Do anyone have anymore ideas?
Modified by Slammed95S14 at 7:00 PM 7/23/2009

[Slammed95S14]

Bump.

I still need help with this problem.

[Slammed95S14]

I found out my problem. It ended up being a bad coilpack. Car runs perfect now.

[s14tan]

I now have this same problem lol.

How did you find out it was a bad coil pack?