Idle problems

Does anyone know what would make the engine idle go up and down from 800 to 1400 RPMs continuously? I have tried the MAP sensor but that didnt help. if the MAP is unplugged it idles evenly but will not stay running when put into gear. How can I check the IAC and TPS? I have the 2.5.

Thanks

does it do this when it is in parked? just keeping ideling up to 1400? becasue my gt did that and found out it was a vaccum leak

Ryder is right about a vacuum leak. This is very common. Inspect ALL the vacuum hoses carefully for cracks from old age.

The air passages in the TBI for the Idle Speed Control can be plugged or the valve itself is sticky from carbon or gook.

Also the EGR valve may be stuck partially open from carbon build up. Again, this is getting common.

Disconnect the vacuum hose frm the EGR valve and drive it a short time to see if that solves it. (Be sure to plug the hose to prevent a vacuum leak.)

I do not recommend driving for ANY length of time with the EGR valve off, as engine damage can easily occur from detonation.

fIEROWISEGUY

Does anyone know what would make the engine idle go up and down from 800 to 1400 RPMs continuously? I have tried the MAP sensor but that didnt help. if the MAP is unplugged it idles evenly but will not stay running when put into gear. How can I check the IAC and TPS? I have the 2.5.

Thanks


Yes it is in park. When I put it in drive the idle drops too low to stay running most of the time. Sometimes I can drive it a few feet then it dies. I have checked all the vacuum lines and have replaced and trim where needed.

What's mentioned above is true. Other causes are:
Clogged air filter.
Clogged fuel filter.
Clogged PCV valve.
Weak fuel pump.
Worn camshaft.
And...

Worn timing gears. This is VERY common on any car with a 2.5L engine. If this is your problem, the engine will make a loud, impossible to mistake racka-racka-racka noise.