hey guys i'm not really sure how ya use these forums so i'm struggling to find the information i need, i've just swapped my vectra gsi for a classic wrx import and i must say i'm having a right giggle driving it!
anyhoo my problem is that when it's cold it idles normally but has an intermittent miss and idles at 1500rpm no big surprise there, however when i'm up to normal temp it's running quite poor when i knock it out of gear when coming to a junction etc the idle drops really low down to like 500 but is really lumpy but will then jump back up to around 1000rpm it'll do this 3-4 times over about 5-8 seconds then settle at 1000rpm but it still has the intermittent miss. on occasion it'll also stall mainly while in traffic and moving a car length at a time. also when pulling away from stationary it's really jumpy until about 3000rpm. it also won't maintain speed i can't just drive along at a set speed as it'll kangaroo so i'm using loads of petrol for nothing.
i've done usual stuff oil and filter change (i was a litre over filled when i got it) so now has 5litres 10w40 semi synth, i've replaced plugs with ngk platinum plugs as recomended i've also tried 2 different maf sensors but where both used parts so i'm going to try a brand new one next week. i've also tried adjusting the icv but no joy
my problem is that being new to turbo's and of course flat 4's i don't know what to do next so any help would be great.
what other sensors etc can cause this sort of problem?