Okay, I did what I was told and at idle I unplugged the IAC, and the car idled down to about 1800 from 2200...what next?

 

I have vacuum leak as well.
This is what I tried, not I know where the leak is.

To rule out idle adjustment and computer idle control:
1. Unplug IS/IAC
2. Turn idle adjusment all the way closed(to the right). This is the idle adjustment below the TB.
3. Make sure the car warm'up, so that Fast Idle Cam/Wax Rod extended all the way. You can push with hand the cam to make sure it does not open Primary Butterfly.
4. Make sure Top Idle Adjustment turn out, so it does not open Primary Butterfly.
5. Run the car in third gear at 1000rpm, don't touch the throtle, let it move on its own. You vacuum should get between 18 to 20 inHg.
6. If not, you have leak either in vacuum hoses or gaskets.

To check vacuum hoses:
1. While engine hot and running, pinch vacuum hoses(big/small) that goes to UIM one by one, to see which one change the idle. I did this, and found which vacuum hoses that leak. If you could not pich, you can unplug it, and close the hole with hand. See which one change the idle.
2. Check the vacuum diagram, see where the vacuum hose lead to
3. Check all the related solenoids to the vacuum line.
4. Check all vacuum hoses in the way, maybe it has holes, or broken, or loose
5. replace, zip tie.
6. Do the whole process again.

If after all this you still have high idle, most probably its one of the gasket. Spray Brake Cleaner around UIM to LIM gasket, TB to UIM gasket, LIM to engine gasket(this one hard to get to)

Good luck,
Reza

 

Oh ya you will get Check engine code 34 when you unplug ISC

 

Thanks, I'll give it a try

 

Add a disclaimer:
Try this at your own risk, I won't be responsible for anything that may happened.

Although I did it to my own car.
And pinch/unplug the hose one by one. take out and put it back in before taking the next one out.

 

Instead of pinching each one, wouldn't it be better to just replace all the vac hoses. Even though it is more expensive it will be better in the long run cause some of the hoses might not be broken yet, but will break in the near future

 

it's definately a good investment, you gotta get rid of those crappy rubber hoses.

 

Well,

He wants to find out which hose is leaking right...
I did this after replacing the hose.
apparently one of the new hose break. This helps me to pinpoint which one leaks without taking manifold off.

reza

 

I'll go over everything that you guys told me today. I hvae to figure this problem out in the next couple of days. Thanks for the information. I'll let you know how it turns out.

 

How is it going?

I got my idle problem fixed.
I got solid 725-750 with TEN grounded.
And the computer puts the idle around 850 normally.

Reza