Is There A Way To Test....

[86custom]

The I.A.C. and the MAP sensor?

I have a 1986, 2.5 4 cyln Comanche with idle issues.

I have done a tune up, plugs, cap rotor, oil and filters change (oil and fuel).

Changed out the some of the vacuum hoses on the driver side of the engine, and changed out the vacuum block at the bottom back side of the TBI, with new hoses. As previous written up here on CC.

Removed the injector and let it soak in sea foam.

 

While the engine trying to maintain an idle I unplugged the IAC and no change.

Is my IAC done?

Also how do you clean the IAC, anyway?

[JENSSEN]

I had a brutal idle issue with my 1988 2.5L ,.. Went through all the usual things to correct it and it turned out to be loose intake bolts, tightened them all up and it's been good since.

[MJRemi]

This link comes in handy for various Renix sensor issues. http://www.lunghd.com/Tech_Articles/Engine/Basic_Sensors_Diagnostics.htm

[dasbulliwagen]

I went throught similar issues with mine when I got it. It ended up being the o2 sensor. Has been great ever since, The factory spec on replacing them was 80,000 miles, so its probably due anyways. Let us know what you figure out.

[cruiser54]

On the 2.5 it's an ISC motor, not an IAC.

 

The ISC moves the throttle linkage and butterfly. The IAC on a 4.0 opens and closes an air passage while the butterfly stays closed.

 

Great idea on checking the intake manifold bolts.

 

O2 sensor wouldn't be a bad idea either as stated.

[86custom]

I have changed out the o 2 sensor earlier but still no change.

Will do the check of the manifold bolts this weekend.

Thanks for your help.