420A Idle Surge help!!!

[Beastman]

I need help, I can't figure out why I have an idle surge but it happened after I replaced my modified performance throttle body to the stock one (idles at 3000rpm). I took off the stock one again and cleaned both throttle bodies with carb cleaner and slapped the stock one back on again with a new gasket from autozone and now it won't fire, it seems like it just stalls right away (or at least wants to fire but won't, if I hit the gas it'll rev up and shut off). I put the performance one back on and it fired up with the idle fluctuating between 6000 and 7000rpm (throttle not closed all the way need to adjust the wire is one of the problems but I don't even want the performance throttle body on it).

The car is a 98 RS. Please keep in mind the car is a non-turbo and I want to replace back to the stock tb because I can't pass CA emissions with it on (came the car when I bought it).

 

[jpmxrider489]

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)

Reading this will help alot. Spray starter fluid in while idle and if the idle picks up then you have a leak there. Try replacing your gaskets. Make sure everything is tight. make sure your sensors are good and what not.

 

[Lavery]

Do you mean 600 to 700rpm for the performance TB? And 300 for the stock TB? If you were not careful when cleaning the TBs with carb cleaner you could have ruined a sensor. Test your IAC and TPS with a multi meter. You can find how to do that on VFaq.

My car would stall when it got up to operating temp but was fine if I kept it moving. It turned out to be my IAC.

 

[bombDSM]

Maybe a vacuum. My car would idle high then die when i forgot to connect the pcv valve.

 

[Beastman]

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)

Reading this will help alot. Spray starter fluid in while idle and if the idle picks up then you have a leak there. Try replacing your gaskets. Make sure everything is tight. make sure your sensors are good and what not.

Do you mean 600 to 700rpm for the performance TB? And 300 for the stock TB? If you were not careful when cleaning the TBs with carb cleaner you could have ruined a sensor. Test your IAC and TPS with a multi meter. You can find how to do that on VFaq.

My car would stall when it got up to operating temp but was fine if I kept it moving. It turned out to be my IAC.

Maybe a vacuum. My car would idle high then die when i forgot to connect the pcv valve.

Thanks you guys for your help, Lavery your advice worked. I cleaned the IAC before installing the throttle body. But now I'm having a new problem and that's a check engine light and after running for a while it fluctuates between 1000 and 2000 rpm. I'll have to find my OBD2 reader tomorrow after work and see what the code is. Maybe I have to drive it around for a while, what do you guys think?

Do you mean 600 to 700rpm for the performance TB? And 300 for the stock TB? If you were not careful when cleaning the TBs with carb cleaner you could have ruined a sensor. Test your IAC and TPS with a multi meter. You can find how to do that on VFaq.

My car would stall when it got up to operating temp but was fine if I kept it moving. It turned out to be my IAC.

Oh and rpm's are measured X1000 .