90 yj 2.5L - idle speed motor/actuator question

[bucklahoo]

1044300

my 90 yj 2.5L TBI wont drop rpms after warming up. it seems that the idle speed motor is not moving, it doesnt move when shutting the motor off either.

where is a good place to get a replacement? how much are they?

if i try to clean it, what do i need to do so i dont ruin it more.



now the idle motor is not giving me high rpms on startup. its actually giving me low rpms which is making hard for the engine to kick over without giving it some extra gas pedal.



i am just wondering...if i take it off and check it out and clean it up is there any special things i have to do to reinstall it. i know the manual says something about having a dealership reinstall it and i have heard people say all you have to do let the computer readjust itself. which is correct?



anybody replaced one before?

[addsig]

 

[hi_c]

1044327

I have a 89 YJ and I had idle problems too. When I ran out of ideas, I took it to the dealership and they informed me that there was a 13 year old recall on my Jeep that had never been fulfilled. The O2 sensor was bad and needed to be replaced. They replaced it for free, parts and labor = $0. Now I idle just under 1000 rpms. It's worth calling them for. A new O2 sensor at the parts store is about $60, so get your VIN number and call them to check for outstanding recalls, it might be worth your while.

[addsig]

 

[MudderChuck]

1044352

Went through the same thing, replaced my idle speed motor, which was a waste of money (didn´t help). Finally nailed it down to a vacumn leak at the intake manifold (loose bolts). My computer defaulted to trouble mode, the idle lowered, but it refused to regulate the idle (no high idle). After unhooking the battery and resetting the computer, it went back to high idle. Could be the same problem for you. But my guess is most any major vacumn leak can cause the same symptoms. Could also be a bad O2 sensor. But on a couple of occasions I´ve replaced the O2 unnecessarily also. If you remove the idle motor, when you reinstall be sure to compress it all the way before trying to screw it back in or it may be damamged.[addsig]

 

[bucklahoo]

1044370

i just had a new remaned engine but in so i am sure that all the manifold bolts and everything are tight.

the motor is not working because i no longer hear it retract when i shut off the motor.

i'll try and find a cheap one somewhere and install it and see what happens.

[addsig]

 

[bucklahoo]

1044838

any other takers?



need some tips on installation of idle speed actuator / motor.

don't want to ruin it upon installation.

[addsig]

 

[MudderChuck]

1044855

I have a tendancy to check the easy things first, before swapping parts out. Jeep has done the same function in various ways, depending on the parts supplier (concessionair) and there partner for moment, Puegot, Mitsubishi, GM, Ford;Chrysler and Mercedes. The idle peed motor, usually opens up a fresh air bypass (bypasses the throttle butterflies). This fools the 02 sensor into supplying more fuel and more idle (same thing can happen with a vacumn leak), the higher idle, is regulated by the computer by RPM. There is a thermal switch in most models, mounted near the temp. sensor that switches the system on and off. A simple continuity check at start up temp. and operating temp. might be helpful, they usually switch about 160 F. sometimes a little higher or lower (the value is usally stamped in the bottom of the switch sensor rod). Low temp. thermostats (or no thermostat) can sometimes mess with the system. There are published voltage readings for the idle motor, that change from model run to model run. That are usually measured by a high impedance tester by pricking the wire and testing in parralel (usually very low voltage). I don´t have the specific values for your model handy. But testing before changing is usually a good idea. Maybe some of the other guys could give you a tip on retrieving the trouble codes from your computer, this should identify a failed idle motor. A simple continuity test of the idle motor, might give a suitable place to start checking. A vacumn test at the intake manifold might also help.[addsig]