1994 high idle
Thread Starter
Instructor
Joined: Nov 2004
Posts: 230
Likes: 1
1994 high idle
Hey everybody, Its been a while since i've been here.
Had a blown head gasket and have finally got my car back together.
It was like the second one in about 3 months!!
Had a bad drain valve on the radiator.
Driving on the freeway and all of a sudden the temp shot up.I got to the side and shut it off but too late,**** me!!!
It would not start after reassembly. Had fuel,had spark,had no compression.
I had adjusted the valves too tight!!
So readjusted them and reassembled.
So now it runs but the idle is about 1850.
I let it warm up and it stays around 215 on the digital oil temp gauge.
The idle does not come down
service engine light on and service asr or abs light on.
I have the FSM but I have a hard time finding anything in them,especially when I'm hot and pissed off!!!
I need a book just to figure out how to use them!!!
Anyway looking for some help and advice
Thanks,Rick
Had a blown head gasket and have finally got my car back together.
It was like the second one in about 3 months!!
Had a bad drain valve on the radiator.
Driving on the freeway and all of a sudden the temp shot up.I got to the side and shut it off but too late,**** me!!!
It would not start after reassembly. Had fuel,had spark,had no compression.
I had adjusted the valves too tight!!
So readjusted them and reassembled.
So now it runs but the idle is about 1850.
I let it warm up and it stays around 215 on the digital oil temp gauge.
The idle does not come down
service engine light on and service asr or abs light on.
I have the FSM but I have a hard time finding anything in them,especially when I'm hot and pissed off!!!
I need a book just to figure out how to use them!!!
Anyway looking for some help and advice
Thanks,Rick
Thread Starter
Instructor
Joined: Nov 2004
Posts: 230
Likes: 1
before idle was around 600
TPS is almost new
IAC , No, not sure how to check.
I guess I'll spent the night trying to find out in the book.
Visual check on vacuum lines looks good.
TPS is almost new
IAC , No, not sure how to check.
I guess I'll spent the night trying to find out in the book.
Visual check on vacuum lines looks good.
Last edited by llesg; Sep 3, 2016 at 10:57 PM. Reason: found out what IAC is
Thread Starter
Instructor
Joined: Nov 2004
Posts: 230
Likes: 1
This car is really giving me a good time!!!
So looks like a lot of the wires got cooked along the passenger side manifold.most of them were melted together,but they came apart when I pulled them,fixed some broken wires to the TPS. I thought that was the problem with the idle.Still idles high 1400.
Now this is weird to me, if I rev it up the speedo will randomly go up to 7 miles an hour!!WTF??? so It starts right up,idles high. while running I disconnected TPS,IAC,MAS, and the other one on the intake boot.
No change in how it runs
Any help appreciated
So looks like a lot of the wires got cooked along the passenger side manifold.most of them were melted together,but they came apart when I pulled them,fixed some broken wires to the TPS. I thought that was the problem with the idle.Still idles high 1400.
Now this is weird to me, if I rev it up the speedo will randomly go up to 7 miles an hour!!WTF??? so It starts right up,idles high. while running I disconnected TPS,IAC,MAS, and the other one on the intake boot.
No change in how it runs
Any help appreciated
Thread Starter
Instructor
Joined: Nov 2004
Posts: 230
Likes: 1
Race Director
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Advanced
Joined: Oct 2016
Posts: 69
Likes: 9
From: Norfolk Virginia
Im not sure about 94, but for 84, if you drive to 40 mph the IACs reset. I was trying to figure out why mine was idling at 1500. Tried this, and it dropped to 600. Give your shop manual a read, specifically in the throttlebody section before you try anything
Team Owner
Joined: Jul 2004
Posts: 28,473
Likes: 3,291
From: Hartford WI
Don't know about a 94 specifically but I'd take the TB apart and clean it first. Take the plate at the top off, take the IAC out, take the IAC housing off and clean the TB and all the IAC passages and the housing. Obviously new gaskets. Reassemble. Check the IAC counts with a scanner and NOT a code reader. See if you get about 20-30 counts with everything but the motor off when it is at operating temp. If you don't, turn the adjustment screw at the TB out, rev and recheck. If you turn it out all the way and still cannot get the target counts, you have a leak. If you can, you have just reset it.
Thread Starter
Instructor
Joined: Nov 2004
Posts: 230
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Don't know about a 94 specifically but I'd take the TB apart and clean it first. Take the plate at the top off, take the IAC out, take the IAC housing off and clean the TB and all the IAC passages and the housing. Obviously new gaskets. Reassemble. Check the IAC counts with a scanner and NOT a code reader. See if you get about 20-30 counts with everything but the motor off when it is at operating temp. If you don't, turn the adjustment screw at the TB out, rev and recheck. If you turn it out all the way and still cannot get the target counts, you have a leak. If you can, you have just reset it.
Thanks, I'll give it a go!!
I kinda like the idea of blowing smoke into my brake booster!
What kind of smoke should I use?????
I will have to look into The IAC counts,not familiar with that, but I'm guessing I will be.
Thanks!!!!!!
Race Director
Joined: Mar 2015
Posts: 15,926
Likes: 579
Not into the brake booster the hose from it to the engine. Just pull the line off the booster and put your thumb over it to see if the booster is leaking. If not get a cheap cigar and blow the smoke to the engine to find the leak.
Instructor
Joined: Nov 2012
Posts: 120
Likes: 6
From: Phoenix AZ
Service your cruise control cable junction. That ended up being my source of high idle after I worked through everything else others have mentioned. You need to lube it and follow the retorque sequence.
Thread Starter
Instructor
Joined: Nov 2004
Posts: 230
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was looking for throttle body gaskets and found them to be allot of money for 3 little gaskets. so going to make them and i'll let you know what happens
Team Owner
Joined: Jul 2004
Posts: 28,473
Likes: 3,291
From: Hartford WI
Instructor
Joined: Nov 2012
Posts: 120
Likes: 6
From: Phoenix AZ
Team Owner
Joined: Jul 2004
Posts: 28,473
Likes: 3,291
From: Hartford WI
Team Owner
Joined: Jul 2004
Posts: 28,473
Likes: 3,291
From: Hartford WI
Always check for "normal" with a scanner. Otherwise it might be "normal" as in the ECM has been able to maintain the command idle but with more adjustment than it should. So if the idle is maintained at 80 counts, it will throw no codes and look normal to you but that means your adjustment window is smaller. So someday if it really needs to open it up, it won't open more than max which gives you an intermittent idle issue.
Melting Slicks
Joined: May 2013
Posts: 2,692
Likes: 349
From: Sacramento California
There is a process for resetting the IAC valve. A quick search produced these:
https://www.corvetteforum.com/forums...re-please.html
https://www.corvetteforum.com/forums...alve-then.html
https://www.corvetteforum.com/forums...procedure.html
https://www.corvetteforum.com/forums...e-setting.html
https://www.corvetteforum.com/forums...re-please.html
https://www.corvetteforum.com/forums...alve-then.html
https://www.corvetteforum.com/forums...procedure.html
https://www.corvetteforum.com/forums...e-setting.html