Ok...I just got my 92 Eclipse, (I just really like the body style and can't beat the gas mileage)...anyways...</P>


Motor was shot and I made the dealer replace it. Drove it for a couple weeks, no problem. Now, when my car idles cold, its fine, but once it warms up to operating temp (right in the middle of the temp gauge...I'm assuming that's about 185F) it surges to 2000 and drops to idle (back and forth until I release the throttle)...regardless of how much I push the throttle. Anyone have any ideas? Idles just fine.</P>


If it was a carbed chevy, I could fix it. I'mspeculating it a faulty sensor that switches the car into "hot run" mode. The mechanic told me my ECU was bad...I replaced it and its still doing the same problem. Anyone have this problem before or have any suggestions?</P>

 

<IMG src=smileys/smiley2.gif border="0">Try doing checks on the idle control motor

 

how would I go about doing that? I am pretty sure its right on my throttle body.</P>


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The other thing though is that it idles just fine......</P>

 

<IMG src=smileys/smiley16.gif border="0">Hi Ryan, you didn't mention if the check engine light is on or not.If it is on you can narrow the problem down a little bit.The light should come on for a few seconds when you initially start the car and then go off if everything checks okay. It sounds to me like dealership left a connection loose on one of many sensors that comes on once the car is warmed up such as the EGR system which only receives vacuum when the coolant temperature reaches a certain point.A vacuum leak will make your motor surge like that as the ECU tries to maintain the correct idle speed.So in concluson i would start with checking vacuum hoses and connectors first.If you still have a problem i'll see what i can find in the factory service manual.