Ok i have a rock hard 800rpm idle. ROCK hard.

This morning i start my car to warm it up. idle shot to ~3000rpms. so i thought "oh, no problem, aws". it didnt drop. i tapped the gas, didnt drop. so i shut the car off. waited a few minutes and started again. 3000 rpms. turned off. started again, 800rpms. no problems for the whole ride to work.

after work get in the car, startup, 3000rpms. turned off, turned on. 3000 rpms. fiddled around with my flashlight looking for vacuum hoses disconnected, everythings fine. start it up, 800rpms. drove around, no problems. stopped to pick up a christmas gift. go inside, 15 minutes at most. came out, start up, 800 rpms.

my idle doesnt bounce or anything. its perfect. the only explanation i can think of is that its the AWS going insane, and not turning itself off.

any ideas? im stumped and its making me mad.

background info, today was around 32 degrees. i didnt have a problem all last month when its been anywhere from 3 degrees to 20 degrees.

car: 1991 turbo. stock.

i also tried starting in gear to bypass the aws, and still 3000 rpms. wtf?!

 

you can disable the aws by unplugging the sensor on the bottom of the radiator on the driver's side. you might have to rev the engine a couple of times to warm the cats up.

 

if its 'bone stock' then you still have the thermowax on the throttle body, which will force the idle up considerably when its less than 70 degrees. Why it was at 800 before, I don't know, 3000 sounds more correct to me.

 

ok so tommorrow morning ill disconnect the AWS from the radiotor, and if it does it again, the thermowax is my problem...

whats the FIX though? i can disconnect sensors all day but that doesnt fix anything

 

i was wondering... if you disconnect the AWS will it hurt the engine any? will it hurt the cats? Also, its my understanding something keeps the engine from fully reving when the motor is cold?

 

Mine started to do the same thing. My motor is stock w/72,000 miles on it. I had a pipe on it but i took it off and put the stock muffs on. this is around the time it started...

 

AWS is disabled when the water temp is below 62*F and above 98*F. Memory on the degrees. I'm sure I'm very close. The info can be found in the online FSM

 

i tried to find the connector today, but i cant find it.... bottom of the rad. on drivers side? i reached down and felt through all the foam on the bottom but i couldnt find it :/ i really cant get to it from underneath without a world of trouble (jacking up, taking off underbelly tray, then putting it back on, etc etc)

anyone want to help me a little on the location?

 

If I recall correctly, thats only on the S4's, not the S5's.

 

what can i do on the s5

 

??

 

WRONG
Jesus christ, i hope NOBODY pays you to work on their car

 

wait 10 seconds till it comes down????

 

wow the whole point of the post was that it DOESNT come down for like 2 minutes.

 

I'm not getting thru. The AWS does not function below 62 degree F water temperature. You said it was 32 degrees and I assume on the first startup the temp of the water was less than 32F.

I'd suggest the bac is sticking.

Upon START, the BAC goes to 100 percent open as long as the key is held to START. So I think it is goind 100 percent open and sticking after you release the key to ON. It could be a icing condition that goes away once the water warms up.

 

i had something like that happen to me, idle was perfect and everyso often at start up it would jump to a perfect 3k rpms and if i stepped on the gas it would go higher but not lower than 3k. id turn off the car, pump the gas and start it and it would work just fine. turns out one of those plastic tabs that secure the harness that runs in front of the intercooler had cracked and shifted so sometimes it would catch the throttle by the tps and hold it open, to a perfect 3k rpms.