95 eclipse RS.

[slammed_eclipse]

I have the 1995 eclipse rs 2.0 ltr 5 speed. a few months ago it started idling funny.>> when i start the car with in 3-5 mins of it being started it will jump from normal idle to around 3 grand and then back down and it will keep doing it over and over and will not stop until the car is shut of.. now with it doing this if you go in and hit the gas to try to stop it it will rev up to 4000 and hold there for a few mins and then it will finally start to work it's way back down slowly. when it finally get back down to normal RPM it will repet all over again. normal idle to around 3 grand then back down and back to 3 grand and it only take about 2 seconds for it to do this once it start... it is like someone is inside the car pushing the gas and letting off but there is no one around the car... i have ohmed out a few things and by the book they all check out ok but am not conviced it is. the check engine light has not come on with it doing this and that is what has threw me for a loop. usually the engine light comes on and i can trouble shoot it myself. i have even went as far as to take it to have a computer put on it to see if the light was burned out but nothing. this problem presists even when i drive the car and stop at a stoplight. Thanks for help everyone.

[david-b]

Welcome to AF! Thank you for being as descriptive as possible.

Firstly, check the Idle Air Controller (IAC) to see if it's functioning properly. You said you have a book, and it has the proper method for testing it. Replace if need be.

If all good, pull the throttle body off the intake manifold. It's held on by x2 13mm bolts. Use throttle body cleaner and spray down the flapper. Also, pull the IAC and TPS and clean all the little holes and divets.

While the throttle body is off, replace the throttle body gasket. These are usually about $3 at the parts store. Lots of time, bad idle is caused by this gasket leaking and letting air bypass the throttle. You can also test this first by spraying soapy water on the throttlebody and seeing if it bubbles. Install back together. Torque bolts to spec.

Lastly, check all the vacuum lines. Again, you can spray water on the lines to see if they bubble. Also, listening to them with a stetsoscope will help as well. Listen to air leaking. Can also take off the hose, clean it and blow into it to see if air escapes. Replace as nessecary.

Hope these help.