I recently installed spacers from Outlaw engineering, and when I first installed them I bypassed the throttle body's coolant lines. Soon afterwards my car started to idle surge from 750 to 1600 rpm and continually go up and down, but it does not do this all the time. Sometimes, when you turn the A/C on, the rpms will drop to 500 and the engine feels like it wants to quit. Again it only does this occasionally. I have no VSA or check engine light lit. I recently read on Outlaw engineering's website that they do not recommend disconnecting the throttle body's coolant hoses. So I reconnected them and disconnected the battery to clear the computer. But it is still acting up, Did I fry my IAC from disconnecting the coolant lines??

Has anyone else experienced this???

P.S. I have an 03 Type-S with a AEM CAI, and I have been a lurker for a long time which makes this is my first official post, so greetings everyone!!!!

 

You didnt fry any thing from removing those lines.

There are 2 causes for your symptoms.

1. The iac valve. Try taking it off and cleaning it (also make sure its connected)

2. You have a vacuum leak. Make sure you have all the bolts torqued properly and gaskets are seated properly

 

Thanks for the info, I guess I'm off to tackle that IAC.

 

let us know if it helps.

 

vacuum leak....i forgot to plug a hose when i cleaned my intake mani/egr had same simptoms in my 99. let us know

 

my idle goes from about 750-500rpm when im at a stop light. only happens from time to time. would this be the same problem asmohenny had?

 

Wow, I think my car is possessed by an evil samuri spirit or something. I haven't cleaned the IAC yet and yesterday my girlfriend drove the car to the store and it freaked her out, because the VSA, check engine, and ABS lights all came on and then the car shook a few times. I have seen other threads citing these as symptoms of a bad IAC, so I was going to clean it this afternoon. I drove it to school this morning and the check engine light was staring me in the face all morning. So, I was on my way to autozone to pull the engine code and right when I get there, the light went out. Friggin weird, so I revved it a few times, turned it off and on, drove it around, etc. Idles perfect and the check engine light is still off! I have owned a lot of cars, but this is the only one that has seemed to like to mess with me. This whole IAC deal, the climate control went out and started working again an hour later, and one time the hood lift blew out and the hood smacked me in the back. I wish carfax would name the previous owner, because I think it might have been Stephen King!!

 

Since you said you bypassed the coolant lines, I would make sure to bleed the coolant. I know with my Legend, surging is usually because of air in the coolant.