Hi Everyone

i recently posted about a potentially dodgy MAF - i took the MY98 in under warrenty and after resetting everything on the car and cleaning the idle valve everything was fine

HOWEVER, a few hundred miles later the following is happening

Car idles at approx 900rpm - the needle is rock steady, but you can feel the engine is VERY unbalanced to the point i am being gently shaken in my seat.

RPM then drops to approx 400
and then slowly climbs to about 750 and runs nice and smoothly

then depending on how it feels it may do it again or wait until the next set of lights.

It hasnt stalled yet.

Any ideas on possible problems - i had recently filled up with Optimax from a garage in Hemel -should that make any difference

could this be a fuelling prob? - MAF or something else???

thanks
Mitch

 

I have a MY00 Impreza WRX (U.K Version)with a Dawes and ITG filter and Denso Ik22 plugs as the only mods.

The car has had all these mods for over a year and has wirked great until now.

The car is going to the dealer(Dawes will be removed first ) tomorrow as I am having idling problems with it. It idles up and down +/- 200 RPM, and if reved in neutral it wants to stall before stabilizing at 800 +/- 200 RPM.

The Autometer AFR shows the fuel ratio behaves the same as it did before the idling problem, boost is fine and the car runs perfectly except for the idle issue.

For this reason I tend to think that it is more likely the O2 sensor rather than the MAF sensor.

I will check the filter and box to see if there is any "green gunk" as has been reported on this site by many people.

Does this seem to make sense to anyone out there?

Comments would be appreciated!!