VR6 OBD2 high idle issue

[Database14]

Hey people.

I have a high rpm @ idle (1500 rpm) when the car is getting warm.
When i start it cold the rpm's seem about right (1100 rpm) but when the warm up cycle is over and the rpm's are supposed to drop, they climb instead.

I have to say it never really idled well, always a little higher than it should (around 980 rpm on a great day) Did the idle reset procedure many times before to try and correct this problem (unhook battery for 1/2 an hour plug the battery back and leave ignition on for about 3 minutes, it works for a while but now it started to idle high again last night leaving work.

did so far.

Checked the ECT:

-From a cold start, temperature climbs steadily up to 90 celcius when monitoring it
with the VAG-COM scan tool. (Tried 3 different ECT's i had lying around and
tested the resistance value) all of them where ok (Blue one with 2 pins).


Checked for vaccum leaks:

- Replaced the lines from intake manifold to FPR and Check valve to secondary air
No leaks anywhere coming from the intake boot.
I don't believe it's a leak at all because the engine would either die (major leak)
Idle erratically or throw you a lean condition code (Idle is really steady but high
on mine). Unless i missed something.

Throttle body:

- Opened it up and cleaned the circuit board (even though the rheostat was
immaculate on TPS) Butterfly and interior is all washed super clean and opens
and closes freely.


FPR:

- It was bad at one point (pickup screen split in half) ran super rich with no
codes (no brainer) and replaced it, works good.


Code active right now.

- P0501 (speed sensor) but has nothing to do with idle


I've done alot of digging on these forums and some troubleshoots came really close but in the end the recommended fixes where already checked and confirmed not to be the issue.

I'd really appreciate some brain storms here (minus the ones i've listed above) and any data you can throw at me to verify, i'm sorry if this post has been redundant for some people, but none of the fixes i could find corrected the issue i am having. Ask me any questions you want, i'll be more than happy to answer and if this post can help somebody else with this problem.that would be awesome.

Thanks in advance.

Marc.

[SilentDawn]

I've never seen a VR6 idle high like that with no codes.

Just some suggestions, some you may have already looked at:

*Make sure the throttle plate is closing fully. Make sure the throttle cable isn't holding it open a hair. The throttle cable should have a little slack in it.

*Unlikely, but unplug the MAF sensor while idling and see if the idle goes down and stabilizes.

*Sometimes the SAI system can cause a high idle, but it will throw a code UNLESS the ECU is chipped to ignore the SAI.

*Maybe the PCV valve is cracked?

*I would think you would be getting an "idle adaptation at limits" error code. So its a possibility that you've got some corrosion going on at the ECU connector or at the round engine connector. Look carefully. Corrosion can cause weird stuff to happen and sometimes not throw codes, or throws bogus codes.

[Database14]

@ SilentDawn

Thanks for the reply Buddy.

Here is where i am as of this morning before reading your suggestions.

Took off the throttle body (for the 3rd time already) The boot has no cracks whatsoever.
Cleaned the ever living **** out of it with the TPS/IAC cap off

Vehicle running at normal operating temperature, unplug the maf (runs like ****) plug it back runs like a charm but 1500 rpms same with the TB connector, idle does not correct itself but that is the extent of it.

Round connector, ecu connector, TB connector and MAF connector all cleaned with electronic cleaner for the 3rd time. when i put the car together i even untaped the engine wiring harness so i could follow each wire and look for corrosion cracks in the insulation so i would not have this problem later on, and retaped it with extreme care.

I scanned again this morning with VAG-COM. (no codes except the p0501)

Looking at engine data though

weird thing is it's always reading Part TP
Range of O2s is -22/-18 %

Battery voltage is cosher @ 13.9v constant
Again ECT is @ 90 celcius

I was contemplating replacing the throttle body but it's pretty expensive to just ''try it''

I've done all your suggestions so far.

Anymore Ideas

Marc

[Database14]

Solved it!

Butterfly shaft was out of place with the plastic cable retainer, weird never seen one do that.

might come looser over time but for now i dont have to buy another throttle body weeeeehooou!

Thanks for the advice.

Marc.

[syn52k]

my vr is a OBDII and im having the same issue i did everything you did and have the same out come, it doesnt idle high everyday but lets say 7 out of 10 of the time it does. its driving me nuts and i have looked up so much research nothing i might go and try a new MAF ecstuning has a mtc brand for 100$ anyone have this one installed on there vr? also any more suggestions?