ok im having some issues...
first off about my car i have a 1997 eclipse spyder gs thats now a Gst. it has the 4g64 with 2g 450cc injectors aresistor box and as16g. it idles at about 12hg of vacum.never boosted above 8. for management I have a safc2 and a dataloger.

now to my problem is that at idle when there is little to no load it misfires on a cylender but it does it about every3-4 seconds. and when i rev it up in nuetral to about 25000 to 4000 it will run good then misfire and drop about300-400 rpm. i cant figure it out.

i changed the plug wires about 3-4 months ago and changed the plugs twice this past week to fix it. it seems like its idle surge but it doesnt rev up like you would think it just cut out then back up. could it be a badinjector?

 

maybe a tuning problem

 

i dont know but when i was watching the stft it would be between 7-10 then when it would miss it would drop to-4.would the safc cause this?thats why im thinking i might be a bad injector. also i have read that when the capacitors go out it does this. how can i check the capacitors in the ecu?

 

well u can take it to the place that tuned ur safc and have them check it out and tell u whats wrong and or take it to the place that built/installed ur setup

 

wait so you've changed the plugs twice in the same week? are they fouling out or gettin full of oil? i think that means you have a bad gasket that needs replaced, then your plugs wont keep getting crapped up and you should stop misfiring

 

Wow good answers jason. Yea a tune with ansafcis gonna cause his car to missfire at idle .

Sounds to me like you might have a vaccuum leak somewhere. How does it pull during full boost and what do you A/F ratios tell you with the logger. Does it missfire at all while your under load. I dont think its your ecu.

 

i installed it all my self and tuned it all my self.

as for the plugs nothing wrong just replaced them to see if that would fix it since it was cheap and figured hey 1 set is a 7 and the other is a 6 so even if the 7 heat rangeset doesn't work ill have themfor when i boost it higher later.

as for pull under boost it pulled reall good a while back and now it has fallen off a bit but not much if at all.

also it doesnt do it at all with a load except at idle with like the ac on but even then it barely does it. my o2 reading is right around 920mv stock without turbo and safc was 860mv. thanks

 

i just installed a FMIC and that seems to have helped the problem it does it a lot les now

 

i retract my previous state ment i think the car had to releanr since i disconnected the bat. it does it once again.

 

what about the fuel filter, thats a cheap thing to replace just to see if it fixes it. Have you tried a boost leak test? thats another thing to think about. Any CEL?