Coil pack problem? RB25DET S1 lock up @ 5K

[t_blackout]

After last problem.I 'm now en count the new problem ,and it seem to be involved the last one.

about a week ago I 'm just found out that the car can't rev above 5000 RPM at all.It went misfiring all the way down when I hit that point.As I observe this condition the boost are came to quickly ,but there is nothing else on the misfiring.

Today I get the car to the shop ,and went for full testing with neutral full-throttle.the result is the motor didn't kick to the rev limit .it appear to be only rev up at 6260 RPM for the max I can push them ,then misfiring.

I 've heard that this symptom could be the coil pack went out. Is it be that? Thanks every one.

P.S. my car are now set up it all stock of RB25det S1 ,after the last one.Stock AFM ,No tune on AFC ,and stock boost no leak.

[jrock7885]

well When you say misfire when at 5k is does it sound like a wrx when misfiring or is it breaking up when you get into the 5k range. you need to supply more info because I just went through a series of these problems but it is fixed now so I might be a little help.

[t_blackout]

Thanks,man.

The 5K problem issue when it get misfiring it sounded still like RB just bang bang !! like I hit it Rev limiter. Then, No rev up .in throttle with no load (Neutral) it can rev up to 6260 RPM by the ECU count from AFC neo.

Another things I observed this condition is when I drive the car sometimes it like the car get cut by ECU but just a few second the you can throttle it.It is still little more split that are much I can explain to you. But still hit 5000 RPM cannot go further from there.

I'm now replace the spark plug with BKREIX7 0.8 Gap from NGK. No coil changed yet.the car now return to stock setting except crank sensor alignment.

Help me please

[jrock7885]

Ok well I'm sure that if you have been searching on here you have seen the most people that have break up issues start with the the cheapest solution which is getting new spark plugs and gapping to 0.8mm which is what kind of cleared up my misfire at high rpm's. after that my car started sounding like a wrx skipping bad, I then tryed the whole coil pack swap around and then checking for spark which gave me nothing because my coi packs where only messing up under load. I swiched my coil packs out for gm coil packs and BAM no wrx sound or (skipping). Ok so the car drove fine for about a month and then it started breaking up again in the 5k range WOT I tryed spark plugs and didnt change anything checked timing everything was good. I changed my MAF to Z32 Maf and my misfire went away completly and the car drives like a dream and has been for the last yr. check your ignitor as well you can go to a junk yard and find a j30 ignitor to test with but make sure to re pin the 6 and 7 pin plug or atleast thats how it was on my RB20. Check your injectors because i have seen them cause problems like this oh and last but not least i dont know what fuel pump you are using but those can cause a miss at high rpm's if its going out atleast that's what happened to my wifes rb25. I have also cleared a misfire in high rpms by just changing the fuel filter. Ok Im done and in any way am I gonna take credit for this info because when I was have these problems for so long i foind all of this info through the search on this forum so if I have left anything out feel free to add.

[t_blackout]

After all I read you post.it seem to be this 5K lockup issue is far more advance than I thought ,but it is OK that not seem to be the Knock sensor as many people told me.

So as my critic it is appear to be

fuel pump
Fuel filter
Coilpack
Spark plug - the gap problem
,and the grounding wire
the maf

I used to be using Z32 Maf before,they seem to be fine ,so I will check it,Thanks for the advice

[t_blackout]

Well ,yesterday I go for testing by put back Z32 AFM .It appear that condition have gone but still split allthe way which I think there are 2 source from this.

1. my clutch is very slippy .I am to replace it soon
2. I heard that there are some boost leak. I will check it ,but the mechanic report that it sppear my exhaust gasket are become leak.

So, What do you think?

[marshallpre1]

I had a similar issue with mine. Previous owner used crappy plugs and when I checked them the gap was HUGE. Replaced them with NGKs and the problem was resolved completely.