Could Bad 88 IAC MOTOR-SENSOR Kill CAR?

[badabing9]

damn these 88's!....could a misadjusted or bad IAC MOTOR cause a car to
stall - stop running while actually in motion or does it just come into play while car is at idle at light or while in park. i keep having this re-occurring problem with my car dying momentarily while driving it.

replaced;.....
plugs,
cap,
coil.
distributor ignition module inside distributor,
electronic pick-up coil inside distributor,
electronic spark control module,
both maf relays (maf is good),
adjusted and checked tps,
all grounds accessible to me,
fuel filter,
fuel "sock" in gas tank (this is not a fuel pressure problem as car has dyed 1x in driveway with fuel pressure guage connected).

when it died today, their was no ses light on, just the battery light as indicated on the information panel on dash.


never throws a code so-to-speak and ses never on indicating a fault while driving or when i restart my car. if car dies, i think (if i remember corectly, there are a few codes stored because there is a domino effect of system failure. i don't think that it is the car's computer. i can run a diagnostic with an autoscan 6000 if someone car take the time to read it and give me their opinion. any help or sugestions would be appreciated.

 

[Agent 86]

IAC is self adjusting. If it's bad it could cause stalling at idle but not under normal driving conditions.

Good luck with the gremlin hunt

 

[tyrel]

It's my understanding that the IAC is for idling only, I can't imagine that it would cause the car to stop running while you're driving. When all else fails I would strongly suspect the ECM itself. It is rare, but they can and do go bad. A bad battery and/or alternator could also cause the problems you describe, you know the old story, the battery is dying and the alternator works overtime to try and charge it, and you fry the alternator. Or the alternator is dying and it isn't charging the battery or powering anything else. The alternator/battery thing has caused me more problems than anything else on these cars.

 

[badabing9]

It's my understanding that the IAC is for idling only, I can't imagine that it would cause the car to stop running while you're driving. When all else fails I would strongly suspect the ECM itself. It is rare, but they can and do go bad. A bad battery and/or alternator could also cause the problems you describe, you know the old story, the battery is dying and the alternator works overtime to try and charge it, and you fry the alternator. Or the alternator is dying and it isn't charging the battery or powering anything else. The alternator/battery thing has caused me more problems than anything else on these cars.

thanks for reply. alternator and battery are new and have been checked. the alternator pully separated a month after i got the car and the battery was on it"s way out a month after that. most of the things i replaced were as a result of a standard tune up i was doing or going to do anyway. i hate the "shotgun" approach to replacing items in troubleshooting my car but, i have done everything in steps for probability. may check my local "advance discount auto parts" or "pep boys" here in orlando, florida for prices on ecm's.......

 

[jsinga]

I think you need to check 2 things:

1. when the car is idling unplug the IAC. Does it stall?
If it does there is a screw up there under a plug for minimum idle speed. Get a book and adjust it. The car should not die, should slow to @ 500rpm

2. Check throtle body for build-up. Get carb cleaner and a toothbrush and clean as far back as you can reach really good. The IAC passage can have gunk in it and cause problems.

The IAC works whenever the throttle is closed. It can cause the problem you describe. The ECM should open the IAC as necessary to keep the engine @ 900rpm with a closed throttle while coasting.

Make sure all your grounds are clean and tight. Some really wierd problems are fixed by cleaning and tightening grounds under the hood. A grounding problem is not likely to throw a code.

thoughts from the backyarder from hell...

JS

 

[badabing9]

I think you need to check 2 things:

1. when the car is idling unplug the IAC. Does it stall?
If it does there is a screw up there under a plug for minimum idle speed. Get a book and adjust it. The car should not die, should slow to @ 500rpm

2. Check throtle body for build-up. Get carb cleaner and a toothbrush and clean as far back as you can reach really good. The IAC passage can have gunk in it and cause problems.

The IAC works whenever the throttle is closed. It can cause the problem you describe. The ECM should open the IAC as necessary to keep the engine @ 900rpm with a closed throttle while coasting.

Make sure all your grounds are clean and tight. Some really wierd problems are fixed by cleaning and tightening grounds under the hood. A grounding problem is not likely to throw a code.

thoughts from the backyarder from hell...

JS

thanks for reply. i have checked as many grounds as i can find and all appear to be ok. the car only will die when travelling down the highway at any given speed. you have stated that the iac comes into play when the car is idling, however, it is not happening at idle. the throttlebody has not been cleaned but, a visual inspection the other day found that it was clean. i have not messed with the iac as of yet.