89 base idle setting
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Joined: Mar 2016
Posts: 53
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From: Dallas TX
89 base idle setting
Hi, my 89 6speed car has a rough idle problem for a long time. and when I try to set the base idle, it won't idle after I jump the pinA and pinB, and disconnect the IAC. I try to adjust the idle screw, but don't work. Anybody know why I can't set the base idle? the engine has just been rebuilt and the wire is new. Thanks
Team Owner
Joined: Jul 2004
Posts: 28,372
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From: Hartford WI
Hi, my 89 6speed car has a rough idle problem for a long time. and when I try to set the base idle, it won't idle after I jump the pinA and pinB, and disconnect the IAC. I try to adjust the idle screw, but don't work. Anybody know why I can't set the base idle? the engine has just been rebuilt and the wire is new. Thanks
What exactly do you mean by "but don't work"? The basic problem with the way you are setting it is that it will ASSUME much, know little. Is your timing correct? Are you having air leaks? Is the tach right?
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Joined: Mar 2016
Posts: 53
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From: Dallas TX
The engine has been rebuilt but did you clean the TB? I clean the TB by removing it and then taking the top plate off, the IAC and the IAC housing and then clean the passages. After that, I run the car till it is hot, shut everything but the motor off and check it with IAC counts.
What exactly do you mean by "but don't work"? The basic problem with the way you are setting it is that it will ASSUME much, know little. Is your timing correct? Are you having air leaks? Is the tach right?
What exactly do you mean by "but don't work"? The basic problem with the way you are setting it is that it will ASSUME much, know little. Is your timing correct? Are you having air leaks? Is the tach right?
Team Owner
Joined: Jul 2004
Posts: 28,372
Likes: 3,260
From: Hartford WI
I generally don't like to use a smoke machine because you can miss small puffs. I use a Snap On MT2500 or a Auto X-ray. So if you are hot and everything is off, you are looking for 30 IAC counts, give or take a few. IF it is lower than 30, it means the computer is seeing that it has more air than it needs and hence it closes up the "air leak" which is the IAC. I turn the screw out, rev and repeat. I keep doing it till I get target counts or the screw is all the way out. If so, there is a leak somewhere.
Thread Starter
Advanced
Joined: Mar 2016
Posts: 53
Likes: 28
From: Dallas TX
I generally don't like to use a smoke machine because you can miss small puffs. I use a Snap On MT2500 or a Auto X-ray. So if you are hot and everything is off, you are looking for 30 IAC counts, give or take a few. IF it is lower than 30, it means the computer is seeing that it has more air than it needs and hence it closes up the "air leak" which is the IAC. I turn the screw out, rev and repeat. I keep doing it till I get target counts or the screw is all the way out. If so, there is a leak somewhere.
Team Owner
Joined: Jul 2004
Posts: 28,372
Likes: 3,260
From: Hartford WI
ALDL to USB, yes. Not sure what software you are using but if it cannot communicate, is the baud rate correct? Some have mentioned that. Not sure. Mine that I use rarely enough I have to relearn it whenever I do seems to work just fine.
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
Some of the Red Devil River cables were not wired correctly for Corvettes. The cable expects data to come out on pin M instead of pin E. I know they rewired a cable for at least one guy. Call them and see what they say.
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