super amazing HIGH idle --- Please HELP!!!

[silverQ]

Hello I have a '91 Q45 and seems random but like 1/2 the time my idle shoots around 1.5k to 3k after warmed up in park or N (seems more common after harder driving). Also always when i first start the car cold it kinda seems to surge to like 2k and falls to the 1.5k like it should for 30 secs but it never comes down after 30 secs to like 700-800 rpm like it used to. This all started after I replaced some injectors that failed .. bit like I say the other 1/2 of the time it idles perfectly like it should. I have witnessed the idle drop almost mechanically like 300 rpms at a time to the proper idle a few times so I really don't think it's any bad hoses or connectors(maybe never can tell) .. but I checked them to be sure. Please help as this is making me want to push this normally amazing car off a bridge .. thanks

[maxnix]

Without any maintenance history, it is very difficult to comment.

Have you established all your vacuum hoses are intact, soft and supple, and not brittle?

[1990Q45'r]

Sounds like air bypass valve might be dirty/sticky? Check to see if electrical connector Disconnected/loose?

[DrewQ45]

Without any maintenance history, it is very difficult to comment.

Have you established all your vacuum hoses are intact, soft and supple, and not brittle?

Sounds like Maxnix is getting feeling up his Q.... groping under the plenum... "So soft, so supple!"

[squeefoo]

Check your Throttle Position Sensor. Did you move it to put the injectors in ? Check connectors for corrosion?Do you have an FSM? Ohmmeter?

We need more concise info to help...

[Raxephon]

Check your Throttle Position Sensor. Did you move it to put the injectors in ? Check connectors for corrosion?Do you have an FSM? Ohmmeter?

We need more concise info to help...

Just in case he doesn't........... '94 Q45 FSM http://phatg20.net/modules.php...d=203

[silverQ]

Without any maintenance history, it is very difficult to comment.

Have you established all your vacuum hoses are intact, soft and supple, and not brittle?

.. actually I pulled the plenum as I had like 7 bad total to replace. I have an OHM meter also but just seems odd as like it ran good before and runs good 1/2 the time now I have no idea whats up. Where's the valve and bypass located at? Thanks

[Raxephon]

.. actually I pulled the plenum as I had like 7 bad total to replace. I have an OHM meter also but just seems odd as like it ran good before and runs good 1/2 the time now I have no idea whats up. Where's the valve and bypass located at? Thanks

'94 Q45 FSM http://phatg20.net/modules.php...d=203

Its less than 40 megs.
Modified by anlasak at 12:09 AM 3/24/2006

[Raxephon]

AAC Valve Hoses

[Raxephon]

Vacuum Hoses

[Raxephon]

The 3 previous images are for the base model Q45.

Not included in the images is the vacuum line that runs to your brake booster.(That line/hose plugs into the plenum between the runners for cylinders 5 & 7)

[Q451990]

You might also check your ECU temp. sensor... if it's not getting a good reading it may think the engine is still cold and hold it in warm-up mode. You should be able to confirm if the ECU is telling the car to idle high by unplugging the AAC valve. If the idle drops, I would suspect that it's an input to the ECU that's the problem... if not I would think that it's a mechanical issue (like a vacuum leak, ect)

Just speculation on my part...

Heath

[silverQ]

Hello giving update with a fix for the problem.

When I originally removed the plenum to replace some injectors and then

reinstalled the plenum the small coolant hose running to the idle cam assy

(uses thermal wax to control idle) was kinked causing the high

idle. All is now well ..

[Q451990]

That would do it. Thanks for the update!

Heath

[squeefoo]

Hello giving update with a fix for the problem.

When I originally removed the plenum to replace some injectors and then

reinstalled the plenum the small coolant hose running to the idle cam assy

(uses thermal wax to control idle) was kinked causing the high

idle. All is now well ..

Excellent! I really glad you wrote back and told us this.

I've encountered many, many threads where they never write back and say what happened or what fixed it.