My MY98 UK Impreza has developed an annoying intermittent hesitation. When flooring it in either 3rd 4th or 5th (the worst) gear it suddenly starts jerking (nearly putting me outta the windscreen!) and the rev counter drops back. It has the same effect as if I had hit the brakes. It dosent do it all the time though, just now and again.

Strangely enough it had this problem a few months ago but it seemed to go away. I dunno if its a coincidence or not but also the car is very difficult to start sometimes. I have to crank it for a long time and maybe leave it for a while before trying it again. Though its only done this about 3 times.

The car has 30K on the clock and the only mods are a K&N induction kit and Magnex back box.

Any ideas as its really annoying?

Cheers,

Gavin

Oh, forgot to say that it happens when I reach about 4500 - 5000 rpm

[Edited by Gavin G - 12/11/2001 2:15:00 AM]

I am no expert but that sounds like one of the sensors is a problem. Does the check engine light come on at all? There was a thread recently which went through a list of things to check based on symptoms but I cant find it now.

Gavin

Sounds like the boost solenoid is contaminated with oil.

The engine thinks it's overboosting and cuts the fuel resulting in the sudden power loss. It doesn't happen in 1st & 2nd because the engine runs less boost in these gears.

You need to either clean it out with brake cleaner or get it replaced. The problem is usually caused by over filling the engine with oil.

Run a search on "boost solenoid", this topic has been covered before.

Mark

Would boost solenoid cause starting problems?
Check out this thread for starting problems:
http://www.scoobynet.co.uk/bbs/thread.asp?ThreadID=51217

I had some hesitation at low speeds in top gear - not when flooring it though - took it back to the dealer that did the last 30k service they found the knock sensor out by a degree - adjusted it and the whole thing feels a damn site better.

T.