surging idle

I have a 99rs and the car starts nice when cold and idles normal until warm., The the idle drops and surges up and down, it started doing this after I took out the apexi SAFC. I was careful taking it out so im not sure what the problem is. The only mods are exhaust and a cold air intake. any guesses what to lok at/

Rich

 

The Apexi was probably fudging for the improper sized CAI. As much as I hate saying this, put it back in.

 

Ok, as long as you carefully removed and reconnected any wires spliced in or tapped into the ECU harness, then you should be fine as long as you reset the ECU. Do this by unhooking the battery and then stepping on the brake, the lights will discharge any power left in the system. The stock ECU should be able to work just fine around a CAI. My 2001 2.5 RS had no problem, just make sure the ECU is reset.

Also the main thing is that I believe there are one or two wires that are actually cut and spliced into the SAFC to alter the returned voltage to the ECU form the o2 sensor. Make sure that was soldered back together or at least spliced back together.

 

Remove CAI, install stock airbox.

 

Is that a mass airflow car or speed density? I can't remeber.

 

THIS! Unless the 99's had the MAF not the MAP.

If it has the MAP it will be fine. There is something else going on if this is the case.

 

check the gasket on the IACV and maybe take it off and clean it.

heres a link on nasioc.com

http://forums.nasioc.com/forums/showthread.php?t=754873&highlight=iacv

 

Def clean the IAC, it should help alot

 

thanks guys, I will try those things. Im trying to find a stock air box.

today I got a p0146 cel code, I reset it and hasnt came back. But im guessing it will.

I checked all the wires and they were fine, also reset the ecu

 

02 sensors can cause surging idle, but so could a bad IAC or MAF sensor. It should have MAF seeing as it's a 99MY.

 

I tried cleaning the maf sensor, but no difference.

I also got the same check engine light last month when I picked up the car, the idle surging happened after I removed the SAFC

 

Rich, did you have to play with any vacuum lines when you took out the SAFC? Please forgive me if this sounds stupid, but I'm not familiar with the SAFC. It just sounds like it could have a vacuum leak.

 

no, never touched any vaccume lines.

To me thats what it seems like but I havn't found anything bad.