Hi,

 

I am trying to sort a problem with my 94 Impreza WRX. After warmin up and stopping at lights the revs drop either very low or it stalls. Some times the revs drop real low then shoot back up to just under 1K rpm.

 

I have a blitz BOV and blitz induction kit.

 

I have just taken the MAF out and sprayed with electrical contact cleaner and looks very clean. I put it all back together and took it for a run and nothing seems to have changed! :-\ Do I need to reset the ECU for it to make any dufference because i never did this? If so what is the best way to reset?

 

I have also tightened all of the vaccum lines attached to the BOV.

 

Whats the next thing to try?

Well... I'll take a shot at this.

 

Did these problems occur before you put the induction kit etc. on?

 

Almost sounds like a MAF problem. Is the CEL on?

 

These MAF are a little sensitive to change. Take it out and see if it solves the problem.

 

To reset the computer, just disconnect the battery for 1/2 hr. or so.

 

 

Beezer

UK WRX--have you checked for any stored codes in your ECU?

 

A long shot, but sometimes a weak Engine Coolant Temperature Sensor can cause symptoms similar to yours.

 

Good luck.

You could find that your ECU has stored the code for a faulty Canister Purge Solenoid - stuck open this valve will give rough idle on a warm engine.

 

Next I would try with some Redex fuel system cleaner, then move onto cleaning the Idle Air Control valve.

 

 

You can measure the output of the temp sensor to see if it's registering the right temp, just use a multimeter, watch for a drop in resistance as it heats up.

 

However, I think the normal failure for temp sensors is the opposite, rich running and low mpg, because the temp sensor keeps telling the ECU the engine is cold. So probably not your problem.

Morning guys,

 

Thanks for all of your help. I cleaned the BOV out last night and it seems to be running ok. For now anyway!

 

The piston in the BOV was very sticky.... i am guessing it was sticking open a bit.

 

I think i might still check the temp sensor just so that i know it is fine. thanks again guys.