Another 'miss Fire' Thread..

[VLSteve]

Firstly, YES I'VE SEARCHED!!!!!!! - results arent really helping me!

I've got a S2 RB25DET with approx 40k on the clock. Running stock boost, 3" exhaust, near new Yellow Jacket coil packs, BCPR6ES plugs gapped to 0.8

Was running fine until yesterday around 4500~5000 rpm its hesitant with a noticeable misfire almost all the way up to redline. Sometimes it does it, sometimes not.

I put in new spark plugs, checked/changed AFM, checked all vac lines for leaks etc etc and couldnt find anything. All wiring looks ok too.

Any suggestions???

[VLSteve]

Anyone? Please?

[boostn0199]

Try bcpr7es and if you can try another coil pack set to eliminate that probelm.

[paulr33]

misfire is dead obvious

it will loudly pop fart and sound like a shotgon or machine gun

describe the misfire

have you checked the basics such as plugs, loom inspection and visual sight of the coils etc

[cannabiscorpse]

Similar thing with mine mate, could be the ecu. Mine got noticeably worse with the more mods i did. Was very slight with stock boost and cat back zorst, then will full zorst and 10 psi it was made much worse. Having said that, most people on standard boost dont have a problem. (i did)

[Pal]

a guy on here had a yellow jacket fail on him and they weren't that old either

[Rolls]

Same cause as always, running extra boost puts ecu into R&R, running richer makes weak spark more obvious.

Two problems, ultimately fix both, you have weak spark due to old stuffed coils, wrong plugs, wrong gap (I think it is coils here). The other problem is running massively rich due to stock tune and extra boost, get a nistune or PFC and fix the tune up.

You will get better fuel economy, more power and no misfire if you do the above. Usually fixing just one of the above will fix the misfire, but you should fix both.

Boost leak will also cause the similar symptoms due to running massively rich (below 10:1), check all silicon joiners etc for boost leak, though majority of the time it is coils as it is happening at peak torque, if it was happening across the board it would be more likely boost leak.

Edited May 27, 2011 by Rolls

[Gonzola]

Firstly, YES I'VE SEARCHED!!!!!!! - results arent really helping me!

I've got a S2 RB25DET with approx 40k on the clock. Running stock boost, 3" exhaust, near new Yellow Jacket coil packs, BCPR6ES plugs gapped to 0.8

Was running fine until yesterday around 4500~5000 rpm its hesitant with a noticeable misfire almost all the way up to redline. Sometimes it does it, sometimes not.

I put in new spark plugs, checked/changed AFM, checked all vac lines for leaks etc etc and couldnt find anything. All wiring looks ok too.

Any suggestions???

Sounds a lot like what mine was doing, different setups, boost, etc.... for the $30 or whatever they cost try BCPR7ES (0.8).

Can't really explain it myself, but it was running fine then started to miss... miss got worse and worse. Tried new BCPR6ES plugs... no help.

The 7s sorted it.

[SargeRX8]

I had brand new yellow jackets fail in a matter of weeks. One died gave me five running cylinders. Then the misfires started. Try the cheapest, easiest option. Spark plugs. BCP7RES. Cost me $20 for all 6. Then try get some stock coils and fit them of IF the plugs didn't help.

It sounds like a machine gun as others have said. A very fast sequence of fart attacks.