Engine Idle
 

I was wondering if anyone could explain why my car has decided to start idleing at 2500RPM. I have a '94 rx7 and I noticed this behavior yesterday after I installed a greddy type-r blow off valve and a'pex power intake system.
before I installed the aftermarket parts the car was idleing properly just below 1000RPM but now it idles at 2500RPM and sometimes descides to bounce as if were trying to come back down (@2200RPM) and then shoots back up to 2500RPM. If I give it a little throttle when this happens the car comes down to 1500RPM before climbing back to 2500RPM


Thanks in advance for the assistance.

The ECU may be adjusting to get used to the mods. If that's the case, drive it for 50-75miles to see if the idling settles down.

Any one else experience this problem when putting your intake?

Did you take off your throttle body? This high idle (especially if its fluctuating) sounds like a leak somewhere the throttle body and the engine block.

Best suggestion I have is to retrace your steps. Doublecheck everything you did - both the conceptual part (e.g. is the BOV supposed to go where you installed it) and the actual execution (is the BOV welded on securely, without a leak, etc). Since this problem cropped up after your modifications, you know that something you did caused it.

Good luck!

If you think you have a vacuum leak, get some carb cleaner, and spray it around wherever there is a gasket. You will easily be able to see if it gets sucked in by a leak.

thanks for the advice guys but I'm still having problems...here's an update:

1. didn't mess with the throttle body so I doubt that's the problem gave it a look over and everything was fine.

2. checked for vacuum hose leaks...found nothing

3. did not have time to drive the car to see if the ecu is at fault, but I did let the car idel for 15minutes in the parking lot and it's idleing at 1500RPM now and is somewhat stable ....it is still reving up about 200rpms, but not as violently as before.

I did check all of the work I did and everything appears fine. At the suggestion of another person I tried to reset the ecu by disconnecting the battery and letting the car sit for a while with out power. I am hoping that resetting the ecu in combo with driving it for 50miles will have the ecu program itself correctly and solve the problem. If anyone has any other suggestions I'm open to them.

I'll reply after I have taken the car for a long spin.

Well, that isn't the correct ECU reset procedure... you have to disconnect the battery, wait a minute, hold the brake pedal down for a few seconds, then wait another minute before connecting the battery back up.

Try it - might help. I would suggest taking another good hard look at the mods you did just before this problem cropped up.

Good luck.