Now I've got an idle problem!

[bobbo]

I know, I know this horse has already been beaten but I just wanted to get everyones opinions incase I've over looked something...
-I've got new intake gaskets, everything is tight.
-I've sprayed the hell out of every vacuum/intake related fitting with MAF cleaner and haven't found ANY MORE evidence of vacuum leaks.
-I've got the AAC screw all the way in and can't get the idle below 1100. I can turn it in quite a way before it increases rpm.
-I can't get the ecu adjustment to do anything at all.
-The throttle linkage is closed all the way. Confirmed by removing the cable and backing the stop screw off.

The only variable is timing but it's still on the original marks and I've tried adjusting it but it makes the car idle like crap so I think it's pretty damn close.

I've tried following the procedure in the service manual for idle adjustment but I can't get that 250 rpm the adjuster is supposed to provide. If I could get that I'd be perfect. Am I doing something wrong with the ecu to enter the idle adjustment setting? The jumper isn't required for that setting is it?
What is the difference between the tps and the throttle sensor? The manual talks about the two of them. I have the middle wire coming from the top of the tps (white) set to .5volts. Am I checking the tps values from the wrong point? Pics in the manual aren't much help.

Thanks again!

[mcfly]

You followed the manual step by step then?

tps is the throttle sensor. if you are getting .5volts on closed and 4.2~ open then you are on the right wire.

Throttle shaft seals?
dead aac valve?

even worse, maybe you have a dead iacv (i say even worse because it is so far under the mess that you cant get at it without everything out). It is the true idle controller on the rb26.

Are the throttles fully closed when on the stop?(nvm you confirmed) How fast are you losing pressure when you leak test the system.

[bobbo]

I'm going to go through the manual "step by step" again to be sure. I don't see how else I can do the idle set procedure any different on the aac. I was starting to suspect I was using the ecu adjustment wrong or doing the steps wrong as the procedure is a bit vague in the manual.

I'm not suspecting the throttle plates as I've sprayed the hinge points very thoroughly to make sure I wasn't getting a leak there. Apparently that's common.
Dead AAC valvle? I hope not. I did have it apart and cleaned it. It does still have an affect on idle but will not bring the idle down past 1100 rpm. I'll do the diagnostic on it later as per the manual.

I thought the iacv valve was for cold start only. The cold start seems about right at about 12-1250.

I have confirmed the throttle plates are closed fully (nvm?) and what is the procedure to leak test the system. Is that in the book?

Thanks again McFly!!!

[jjskyline]

Have you tryied a ground kit your be amazed at what it can do

[bobbo]

Honestly haven't given it any thought. I think I'll try the Tomei product for the throttle bodies. I think that is likely the problem.
One thing at a time.