hey guys.. im new here and got a slight problem..

ok i have a 97 GS with a 99 GS engine swapped in cause the old engine was blown.. i didnt do the swap myself.. i paid some1 to do it... when it idles in neutral.. it usually stays at 1000rpms... goes up to like 1300rpms then goes back down to 1000.. it does this constantly n sometimes goes below 1000rpms.. any ideas to what could be causing this? and is it normal for the car to be staying at 1000rpms in neutral?

Is it fully warmed up? You probably have a vacuum leak.

warmed up or not.. does the same thing

Is it manual or automatic? Manuals should idle at 850. I've heard that if it doesn't stay between 800 & 900 after it's warmed up it can cause a CEL.

Originally posted by Nemo
Is it manual or automatic? Manuals should idle at 850. I've heard that if it doesn't stay between 800 & 900 after it's warmed up it can cause a CEL.

It can throw code P1294, but mine never did when my idle was at 1200.

Check for tight throttle cable?

its manual and the check engine light IS on..

Scan it or keydance. What are your codes?

find out what your code is first and then I'd start checking for vacuum leaks

I had the same problem. I removed the throttle body, (easy) cleaned the whole thing with carb cleaner. Removed the IAC, ICM and found the plunger inside it was a little sticky. Cleaned it with carb cleaner and no more idle surge or high idle.

BK85