Engine missfire under boost???
 

Hey guys.
I really hope some one can help me here as this is getting me worried now.

I did an oil change about 3 months ago and ever since my MY96 STI has developed a misfire kinda thing under boost. It just happens now and again and usualy when its nice and hot. (not that i boost it when its cold).

I had my engine light come on when i come off the throttle after about 7 seconds. I did an ECU check and it was fault 24. Changed the sensor but hasnt made a diference. Still this missfire under boost but like said, it only happens now and again.

Any one got an idea?

Cheers.

Chris.

I can't remember if the MY96 uses coil packs on each plug or if it has the central coil and leads, but it's either plugs, leads or coil thats knackered. Your weak spark is being blown out under boost.

yeh you have coil packs on each plug - defo worth checking them. Take them out - remove the rubber ends and see if they are cracked.



Andy

I had this on '93 WRX when i first brought it, got the packs checked and the plugs changed and it run fine after that.....mine was a plug breaking down under load.

Gav.

I just put a brand new ste of NJK 7s in not that long ago but didnt check the spacing of the spark electrode. Is that worth doing? My mate was saying last night that if its to far apart then the the spark wont be strong enuff.

The plug gaps should be 0.7mm on the NGK 7's, re-check them and whilst the coilpacks are off also check the necks under the rubbers for cracks in the ceramic as suggested above ;)

Cheers