wilfian

Hi all I have recently purchased a 1994 impreza sti This is my first subaru wich I bought from an import auction.
My problem is that when I drive the car just after its warmed up It runs perfectly but once Ive driven it for about 30 mins when I put my foot down it hesitates Judders drives eraticly at between 4000 and 5000 revs I dont know if this continues right through the rev range as Im too scared to keep my foot down when this behaviour occurs anyone with any Ideas why ???
Thanx

jaytc2003

iTrader: (1)

most likely either plugs or coil packs. Would recommend changing plugs anyway (something I always do on cars that I buy)

wilfian

Today I have noticed that If I take my foot off the acelerator a little at 4000 revs its fine do you think it could be overboosting??

jaytc2003

iTrader: (1)

no, if it is overboosting you will have fuel cut, trust me you will know when that happens as you will probably headbutt the windscreen! (or steering wheel if you are short!)
Trust me, change your plugs first, if it solves it then great, if not at least you have a set of new plugs which wont do any harm. (also cheaper than coil packs) Some people may say its the maf, but that is highly unlikely with your symptoms. It will defo be the plugs or coils

Drift SX

My STI V2 has same problem someone suggest fuel pump, I just ordered one will see how it goes.

pauly

iTrader: (1)

same problem and it does carry on through the whole range recently changed fuel though and thought it could be that but will get some new plugs for it been doing it for a couple of days

Jolly Green Monster

iTrader: (4)

coil packs imho.