just wondering if anyone has gotten a similar problem as me, or maybe has some suggestions to look at......

In the last couple of days I seem to be experiencing a very bad "flat spot" when i'm driving normally. It seems that when I reach ~40mph the power drops off, almost as if i've taken my foot off the accelerator, causing the car to act as tho it were breaking under engine power only... A slight increase in gas, and i mean only a slight one, causes the car to jerk back and the power to pick up again, but until ~55mph the car feels like its "stuttering".

Its almost as if there's a fuel blockage or something and that higher revs unblocks it, but when I drop back down into the lower rev range, it happens again...

Anyone have any ideas of things to look at ??

I spoke to my Scooby dealer and they reckoned it could be the air intake, but I'm suprised that if it were that, its so very precise at being between 40 and 55mph....

Any help would be most appreciated....

 

no one with any ideas or suggestions at all ??

 

You only mention a road speed rather than a rev range. My standard MY99 turbo had an identical problem at 4000 revs in all gears. The problem became worse and worse over a month or two until the damn thing wouldn't go over 4000 revs in any gear and lurched and kangarooed like a mad thing if you tried. I didn't get the problem sorted straight away because my trusted rally mechanic nephew was out of the country. When he did finally look at it he found two faults- one was the lambda sensor (£80 to buy, which wasn't causing the flat spot) and the air flow meter on the air itake (which was). The meter is an expensive part (£200+) but my mechanic says isn't a long job to fit it. It is a known weak point on imprezas, from my researches, and is a delicate instrument that is susceptible to damage by disturbance, so if it is this, get someone who knows what they are doing to fit it. When I got my car back and drove home I realised the car couldn't have been right when I bought it- I thought it was quick then but this was a different class. I hope this has helped, let me know how you get on.

[Edited by Bubba po - 7/23/2003 2:51:00 PM]

 

Don't want to start an Optimax debate but when I switch from SUL to Optimax, after a few Optimax tank fulls I developed a flat spot also. Happened about the 3500~4000rpm range. Switch back to SUL and it cleared itself.

I've also got a P1.

 

Thanks for the info guys.... I'm certainly gonna let the dealer take a look at it and check the air flow meter, but co-incidentally enough.. Ive just switched to using Optimax recently (like the last 3 tanks), so maybe i'll try switching back to the SUL and see if that makes a difference...

Thanks for the suggestions guys.. I'll let you know how i get on..

ATB