# '86 QSW runs rich and cuts out. Help!



## engineered4power (Sep 15, 2009)

Hopefully someone can help me diagnose my problem, or at least point me in the right direction. My car get's terrible mileage (8 mpg) and sometimes it seems to have a miss-fire. It's snowing outside, and at an idle, to car leaves a black spot in the snow. Whenever you come to a stop, it smells like it's running rich also. When I put the timing light on it to set the ignition timing, I noticed that it isn't always firing. I replaced the coil with a new Bosch 00061 coil, but that didn't help. I tried unplugging the mixture control actuator (not sure of the right name for it) on the CIS and that made it idle faster, but had no power so it's not drivable. Also when I plug in the Idle Speed Control valve, the engine revs way up. I'm starting to wonder if I'm not getting a good ground somewhere, and that's making all of the electronics go crazy. If someone can at least point me in the right direction, I'd be very appreciative. I really like this car, but it's starting to drive me a little crazy.


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## 4doorhoor (Aug 31, 2005)

*Re: '86 QSW runs rich and cuts out. Help! (engineered4power)*

One thread is enough.


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## engineered4power (Sep 15, 2009)

I agree that 1 thread is enough, but I don't seem to be getting any good results from my others. If I could delete those I would and just have this one. Me talking to myself on my other threads that no one seems to be responding to doesn't seem to be working.


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## 4doorhoor (Aug 31, 2005)

*Re: (engineered4power)*

Try the I-5 Forum or motorgeeks.com.


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## strictlyA2 (Jul 27, 2002)

*Re: (4doorhoor)*

Have you set the base timing (cam and crank)? My brothers 4000 just did the same thing.... turns out it jumped a tooth on the timing belt. My quantum is acting the exact same way, I have a feeling after running into 1000 snow banks over the past few days it has done the same thing. I don't really have time to look into it... otherwise I'd troubleshoot right along side of you!


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## engineered4power (Sep 15, 2009)

I haven't checked the base timing yet, but I will do that this weekend. The way I read my manual, it looks like I can check it by removing the valvecover and upper timing cover? Hopefully it's something simple like timing. Thanks for the suggestion.


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## eurowner (Jan 26, 2002)

*FV-QR*

Did you Ever have the car running correct?

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## engineered4power (Sep 15, 2009)

No, when I bought the car, it had been sitting for over a year and would barely run. I replaced most of the ignition parts, and that helped. I also reset the ignition timing and fixed some vacuum leaks which helped some. I'm still trying to find the "silver bullet" that will get this thing the rest of the way back to where it should be.


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## eurowner (Jan 26, 2002)

*FV-QR*

O2 sensor hooked up?


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## engineered4power (Sep 15, 2009)

I checked the O2 sensor, and it is hooked up. The sensor wire holds about 0.45V at idle, which I think is good. Not quite sure how to check it better, any suggestions are appreciated.
Update: I also looked at the base timing, and it appears that the cam is 1 tooth advanced. With the crank at TDC #1, it looks to me like the dot on the cam gear is below where the valve cover gasket meets the head. Does this sound like 1 tooth off to anyone else?


_Modified by engineered4power at 11:35 AM 2-13-2010_


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## engineered4power (Sep 15, 2009)

Ok, I reset the cam and ignition timing. Engine definitely seems to pull stronger, but still seems to miss pretty bad at idle. Is there a set amount of time for the O2 sensor to kick in and try to smooth things out? Do I need to do something special to reset the system? The O2 Sensor wire still seems to sit around 0.40-0.45 V whether idling or not, so I'm not sure that the fuel system is closing the loop as I expect it to toggle between rich and lean.


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## engineered4power (Sep 15, 2009)

So over the weekend, I adjusted the "mixture screw". It is the 3mm Allen that is down between the distributor and the air connection to the throttles. I leaned it out a bunch, and it seems to run alot better. The idle air control still doesn't want to work. Whenever it is hooked up, the engine revs to 3000 RPM. Is there some sort of learning that it needs to happen for it to do it's thing? Is there a way to set the idle correctly so that it will work with the IAT hooked up?


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