af908

Guys,

I just rebuilt my engine, dropped it in and it runs like crap!!!

Doesn't idle without my foot on the gas pedal, and anything under 1k RPM and the car shakes

All the vacuum hoses seem to be conected, installed new spark plugs, im out of ideas - sensor maybe?

HELPPPPP!!!!!!!!!!!!!!!

HeepJeeper

TPS but idk why it would shake

Bustedback

Idle Air Control motor handles the idle duties, you sure you have the timing and firing order correct?

af908

Well i have the coil packs, i dont think this can be adjusted..

Which sensor is the idle air control motor? or where is it located exactly, ill try replacing it but i want to make sure i'm looking at the right sensor. thanks.

Bustedback

It's located on the throttle body, looks a little like an electric r/c car motor with a plug at one end and mounts with two torx screws at the other end. It's not a sensor, it's an actuator. Sensors send info to the PCM and then the PCM tells the actuators what to do to adjust and make changes in how the engine runs.

af908

Got it... thanks. Any way to test this to make sure its working properly?

Bustedback

Not without a scan tool. NAPA should have the motor for around 50 bucks.

af908

I've heard that if you plug it in and try to crank the engine the actuator should move?

dilljeepo

What I did to test if my IAC motor was bad is I took it out, changed the plunger (pulled it out first) just shoved it back in without connecting it and see what difference it made a couple times doing that and my jeep fired right up no problem and no rough idling, but it was a little high. I tried taking mine out and starting but I couldn't see anything because it wasn't moving (wasn't because it was bad, it was because while cranking my engine, my weak battery couldn't even turn the motor). Anyway, I left my idle at around 1,100 (only about 500 cold start) until I bought a new battery. My two cents

af908

I will try that today when i get home.

Does the plunger just pull straight out? (asking first before i break anything )

dilljeepo

yeah you need to take out two torx screws, you'll see them on the side of the throttle body, and it just pulls strait out after you take them out. If I remember, pulled all the way out is really low idle, pushed all the way in is a hell bent idle that will get you to 50mph without hitting the gas lol. Anyway, if it runs smoothly when you find a nice idle then you can guess the problem.

af908

So i noticed just now when i pulled the IAC out that it looks like it is fully extended.

Shouldnt this thing retract completely while the engine is off to allow for an easy start?

as a side note, i left the CCV hose unattached by accident (the one that attaches directly to the top of the intake manifold and it ran BEAUTIFULLY... weird, i know.

Carsten

That could mean that you are letting extra air into the intake, the same thing that the IAC is supposed to do in a regulated way. Could have something to do with the problem, but just guessing.

dilljeepo

yeah all the way out (if I remember) was really really low idle/almost no air.
try pushing it in a little bit and starting up again, but put the CCV back on so you can tell if it's the IAC, if you get a nice idle then just screw it back in and leave it unplugged until you get a new one, idle will get a little higher when warm with no control but no biggy.

af908

The thing wouldn't budge. It stays completely extended. Must have locked up on me while the engine was out i guess?

So i'm guessing this is my problem.

Ill order a new one today, hopefully this might solve my "shaking" problem too..