I was reading the directions on how 2 adjust an iac valve in the tech articles. In the article it refers to a "ALDL". My question, is what is a ALDL, where is it located, and what are the A and B pins? Also should I clean the iac first, before I adjust it? Any help would be appreciated thanks alot!!!!



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Bad A$$ Boys Drive Bad A$$ Toys

 

As far as I know the IAC on the 2.8/3.1 MPFI cannot be messed with. You do not want to throw in a resistor to have a "set" amount of resistance because your car may never run right and not be able to handle all the differing conditions.

 

Camaro_hunter_d is confused, and thinks you're talking about an IAT sensor (idle air temp).

Yeah, you should definately clean the IAC (Idle Air Control) valve! Before you do any work on the IAC, make sure you unplug it's connector- and don't plug it back in until the IAC is back in the throttle body. You can clean the IAC with some "throttle body cleaner for fuel injected engines" on a rag.

Also, clean out the IAC passageway: If you remove your throttle body hose, and look at your throttle body from the front of the car, check out the left side, next to the throttle plate. You'll see an curved indentation, and inside that will be a hole, That hole runs inside the TB around to the IAC, and then it goes from the IAC to the back of the throttle body. This is how air at idle will "bypass" the throttle body. Anyway, shoot some TB cleaner into the hole that the IAC comes from- you'll see a ton of black crap pour out of the hole in the front of the TB.

ALDL = Assembly Line Diagnostic Link; it's the connector used to "talk" to the car's computer. It's above the driver's feet, probably covered by a plastic pop-out rectangle. The A & B pins are in the uppermost row, and are the rightmost two pins in that row.

I'd say clean the IAC first. You might not need to adjust your idle speed at all.

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-Tom P (Hot rodded 1986 Firebird 2.8l)

 

Thanks for the help!!! I was having a brain fart when I wrote this. I got it figured out and now it actually idles alot smoother

Thanks again,
Jeff

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Bad A$$ Boys Drive Bad A$$ Toys

 

No I was not cunfussed. I know what the IAT is. It is in(or was) my air box. The IAC CANNOT BE ADJUSTED, as the topic is asking. Yes the passage can be cleaned and what not but the IAC cannot be adjusted. You should not make assumptions TOMP.(especially when thier WRONG.)



[This message has been edited by Camaro_hunter_d (edited October 25, 2001).]

 

The only way I know to adjust the Idle speed is with the set screw that is on the manifold.(that sits on the throttle body by the throttle plate)

 

...which is obviously mentioned in the tech article that OneTireFire was referring to- the title of which is "IAC and TPS Adjustment", which could be read to infer that both the IAC and TPS can be adjusted. I knew what he meant. You're talking about resistance- how would you possibly use a resistor in conjuction with an IAC motor? It's a STEPPER MOTOR. And besides, the article referred to does not mention anything about physically adjusting the IAC motor.




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-Tom P (Hot rodded 1986 Firebird 2.8l)

 

Thanks for clearing that up TomP Basically the only purpose of this post was 2 locate the ALDL connecter. When I use 2 work for Ford Motor Company as a Diagnostic Tech, we only referred 2 this as the Smart Cable. So I wasn't familiar with "ALDL". But after I figured out what the article was talking about, I had no problems at all. The adjustments were succesfull, and now my car idles smoothly. I couldn't believe that my tps was set at .24 or something like that. The only problem that I have now. Is that my tps voltage mantains a steady .54 volts at idle speed....but at WOT I can only acheive 4.26 volts. The book I read said it should be between 4.5 and 5 volts, Do you see any problems with 4.26? And what kind of problems could this cause?

Thanks for any more help guyz!!!

I appreciate the Info



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Bad A$$ Boys Drive Bad A$$ Toys

 

I did what that article said and it did nothing for me i got lost half way through

 

Even with my TPS jacked up to past 0.60 (I think at 0.62?) volts at idle, the highest WOT voltage I ever got was 4.28. Of course, driveability at low throttle suffered, so I put it back to 0.55 volts. But according to the PROM guys, the computer does know this, and enteres PE (power enrichment mode) (WOT) at anything over 4 volts.

Did your car get an extra kick in the butt after this checkup? (It'll probably be easier to pass emissions now, too!)


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-Tom P (Hot rodded 1986 Firebird 2.8l)

 

So your saying that I should be ok with 4.26 volts at WOT?

BTW, the adjustments did help alot. Before the adjustments my car would shake and the RPMs would go crazy at idle speed. Now the car runs nice and smooth. I also noticed a little bit of extra pull of the line aften the tps adjustment.

I sure hope that it helps out with smog, cause that's been my major problem lately.

When I bought the car a few months ago, the girl I bought it from couldn't smog it cause the motor wasn't running. So after I bought it I put a 1989 firebird motor in it. Even though the car is an 1986 Camaro. But I still haven't got it smogged yet I tried once and it just barely failed. But after I got it back home, I noticed that the cat was gutted. So I bought a new cat a couple of weeks ago, So i'm hoping that It will pass now

Wish me luck

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Bad A$$ Boys Drive Bad A$$ Toys