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Discussion Starter #1
I recently purchased a '94 Aero (no TCS) and I'm having an issue where the rpm's hang and even rise slightly between shifts at rpm's of 3000 and above. I did have a bad bypass valve wich I replaced, however that did not make any difference. The only other thing I can think of is a vaccum leak or the AIC valve. I have replaced all of the vaccum lines and the engine pulls decent vaccum (18 in- HG), so I don't think that there is a vaccum leak anywhere. The previous owners were chasing this problem for a while. I found a few bills from two different places. One was from M & M Saab in Woodstock, GA and the other two were just from some backyard saab mechanic. On January 6, '07 the car was taken to this backyard mechanic in an attempt to fix this problem. The bill reads as follows, "clean & adjust throttle body & CIS motor. If this doesn't fix it we should replace the CIS motor." I have no idea what the hell a CIS motor is. I know Saabs very well, but I've never heard of a CIS motor. Does this CIS motor exist? Is he thinking of the AIC valve? On February 10, '07 the car visited the same mechanic and the bill reads like this, "unable to tell if assurance wheel causes engine to run away when shifting." Is this guy just making **** up? An "assurance wheel"? So this guy had no luck fixing the problem, so the car then visited M & M saab on February 15, '07 where the AIC valve was replaced and engine codes were pulled with the Tech II. They charged $125 for the AIC valve, which seems low to me. Isn't a brand new one at least $200? They possibly put in a used one and the AIC valve could still be faulty causing the problem.

I hope someone else has had this problem and can tell me exactly what it is. I found another thread where a guy was having the exact same problem but he never did follow up on the thread, so there was no info to be had from that thread.
 

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Every time my car has done anything like that it was the aic valve. If its in back-wards it will do exactly what you say and the flow arrow is backwards of what an average joe might think... That is how I found out:p

John
 

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Discussion Starter #3
Hmmmm, that's interesting. I never even thought of that. I will have to go take a look at the AIC valve. I'll cross my fingers that it's in backwards!!! Thanks for the tip!!
 

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Guess what? It was in backwards. I flipped it around and now the rpm's drop perfectly as they should and it even idles a little smoother for the most part. I might have to reset the throttle stop screw and the throttle switch, cuz I think the thing is probably way out of adjustment since people have been dickin' with it all this time while the AIC valve was in backwards. The one time it dropped to about 500 rpm when letting off the throttle, so I'm just hoping things are out of adjustment now. I'll have to look in my Saab service manuals for the idle adjustment procedure, unless someone has it readily available. Thanks for the tip John. I'm glad it was nice and easy to fix. I'm wondering if I should get the throttle body and throttle switch adjusted properly and then do some adaption runs. I think this car has been all screwy for quite a while now and the computer has probably learned some bad habits that need to be erased from its memory.
 

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That will be 195.00:cheesy: I am glad I could help... It probably is way out of adjustment now that people were trying to adjust it for the wrong reason. They probably have it adjusted the wrong way too!

I would re-adapt the ecu anyway and it will learn the short/long term fuel trims all over again. Good Luck,

John
 

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Discussion Starter #6
I didn't have any luck finding the Trionic 5 service manual, but I found the Trionic 7 manual. It says to turn the throttle stop screw in 1/3 turn past the point where it just starts to touch the throttle lever and I guess the ECU does the rest. I wonder if that would be the same for my Trionic 5? Tahnks for the assistance. That's the first time I've received the exact fix from someone on the forums.
 

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Discussion Starter #7
So every once in a while the rpms will still stick and continue climbing when lifting off the throttle and disengaging the clutch. It seems like it only does it for a while when the engine is cold. It'll do it so bad that the car will actually drive by itself when engaging the clutch when this problem occurs. could this just be a faulty AIC valve or is there something funky going on inside the Trionic computer and it doesn't know how to control the AIC valve? Could the AIC valve be damaged from having it in backwards? It seems strange that this problem hasn't triggered a CEL. Any help would be greatly appreciated from someone that has experienced a similar problem. I want to make sure its the AIC valve before I spend the money on a new one.
 

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Aic valve. Have you pulled it out and cleaned it out with brake clean and wd40 and compressed air? That helps many times. They do develope dead spots on the motor and it will stick there intermittently. The only cure for that is a new aic valve...

John
 

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Discussion Starter #9
I haven't tried cleaning it yet. I'll give that a shot, then if that doesn't help I'll just have to break down and buy a new one.
 

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I just pulled one off of my girls cse and it was hanging up at idle a little bit and it was full of some kind of dirt and or sandy looking material. I cleaned it with brake fluid over and over and then wd40 and kept blowing it out with compressed air. I got a ton of crap out of it and it just kept coming out. Once I got it fairly clean it did seem to settle down and idle better. No more sticking at 1200rpm.

They can get dead spots on the windings too and there is no cure for that but to either live with it or replace the aic valve.

Good luck,

John
 
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