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My car keeps stalling. IAC to blame? 700 1992

Hello all
Today I was replacing a broken vacuum line and decided to clean out my IAC "while I was in there." I pulled it out and looked at it. There was some varnish on it and some almost gritty looking oil deposits showed up as I spun the valve.

I turned the intake hole down and had the out side parallel to the ground. Holding it like this so the cleaner would drain out, I sprayed Carb Cleaner in it and this removed the deposits. I wiped off as much excess cleaner as I could and then set it up to dry for a few minutes before replacement.

When I put it back in, the car would start and immediately die. I fiddled with it some more while my wife nagged me about us being late for dinner with friends (which we weren't). I took it out and opened the valve. The car started and idled but it bounced between ~1K and 2K. Not normal. I disconnected the thinkg altogether and the car started and ran but the idle was very erratic. Finally, I got the idle fairly normal but the vehicle died once on the way to our friends house and several times on the way home. It required the two footed driving technique to keep it from dying. By the time I got home it had been idling low and when I put it in the carport it was idling around 1500 rpm but somewhat steady.

What gives? I'm going to go try to test it and possibly clean it some more but do these symptoms sound normal for a somewhat stuck IAC valve? What hacks me off is that it was idling fine before I fooled with it. It would dip just slightly as I put it into gear and it had died a few times when cold if immediately put under load but the idle was pretty steady, if slightly low. Now the idle's all over the place. I was cleaning it because I thought there were symptoms of it being a little slow to react. Now it almost seems as though it gets stuck.

I'm going to check it out again now. Anybody had this happen to them?

Thanks
Don
--
92 745T 125K; 83 242Ti 188K - Brick on blocks for now.








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    My car keeps stalling. IAC to blame? 700 1992

    I cleaned it until long after it was shiny. It seemed to move freely and the spring return worked although it didn't feel overly strong. I got between 8.2 and 8.4 ohms across the connectors with a cheap multimeter.

    After reinstalling, the problem remains. If I tap the IAC while its surging, the idle drops to ~1100 rpm and is fairly steady for a short while and then it begins fluctuating again at the lower rpm level. It varies maybe 200-300 rpm. If I tap it again, the revs drop again and so on and so forth until they drop so low that it will stall.
    --
    92 745T 125K; 83 242Ti 188K - Brick on blocks for now.








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      My car keeps stalling. IAC to blame? 700 1992

      The FAQs has a complete section on how to take it apart for cleaning. And how to test the internal windings, and how to test on the car. More than likely, once you get it clean, you'll probably have to clean the throttle body, and reset the base idle. Also covered in the FAQs.








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        My car keeps stalling. IAC to blame? 700 1992

        Don yes IAC is probably to blame, but, check all hoses to and from the iac. I've had a split in one before and it gave symptoms you describe. On my 95 944t i remember going to the parts house and using formed heater hoses to splice in to get me by. BTW i've never had any luck disassembling an IAC to clean it but you might.

        let us know the outcome

        dhalljr







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