Dan@TurboTechnics

Hi Guys,

I am having a problem with my RA at the moment. It seems to be going into limp home mode, limitting the revs to 4000. I have checked the error codes, and it comes up vehicle speed sensor. The speedo and rev counter are working fine, which puzzles me as to why it has thrown up this error. If i reset the ecu, it's ok for about twenty minutes, and then it kicks in again. I haven't got round to checking the sensor in the gearbox, or the speedo cable itslef.

One thing i have noticed is that sometimes, the revs drop low as you let the engine idle back down. Not low enough to stall, but lower than they should be.

Being a relative newbie to Imprezas, i was just wandering if anybody has come across the sam problem, and how was it resolved.

Thanks in advance,

Dan

Graz

What year of manufacture is it? The revs dropping low thing is often an indicator of MAF (air flow sensor) problems, though less likely on older cars with a hot wire type MAF, the MY99/00 film type MAF sensors are notoriously bad for dying.

That said if the ECU is throwing an error for the speed sensor then that is why it's going into limp mode, you need to sort that first.

Dan@TurboTechnics

The car is a 96 n-reg. I will see if i can check the Maf out, maybe borrow another one to see if that cures it. With reference to the speed sensor, i did notice this morning that the milometer on the car has stopped working. I did about 5 miles this morning, and it is still reading the sam mileage as it did last night. Could something have come loose behind the dash?

wilkoca

Its deffo the TPS i guess its error code 33.

Same occured with my 2000 Sti had the dipping revs and limp home all i did was clean it out and prob solved.the throttle position sensor is on the the top or to the side of the drivetrain/gearbox.
Sounds like yours has just worked loose.

cheers
Chris

Dan@TurboTechnics

Wilkoca - Thankyou. Just to clarify, did you mean VSS (Vehcile speed sensor), but yes it was error code 33.

wilkoca

Same thing mate

Plus i found if you stick a bottle of injector cleaner into the tank it cleans the carbon off the throttle plate and insures a proper signal from the throttle position sensor.

cheers
Chris