Hello,

I purchased a very nice 1981 Camaro for my son (he must pay for 1/2 of it) and I purposely picked one up with a v-6 until I know he'll be able to handle the power of a 350, and we'll swap in a 350 later.

The car needs a valve job but it also has a drive-ability problem that I'm looking for help with. The car dies frequently when coming to a stop or driving slowly but seems to drive very well when at speed. I assume its running rich at low idle which is causing it to die. Lots of smoke when idling and while part of that is because it needs valve work, I think some of it is because of the rich condition. Again I'm not familiar with this engine or the carb (which I think is stock) so any help is greatly appreciated.

 

HI...Welcome,
I think a complete carb rebuild is in order. There are many reasons for a rich idle. Bad power valve, stuck choke, idle circuit clogged, etc. A good cleaning and rebuild will likely fix the issue. Good luck

 

Welcome to the forum Brian! I would agree that the carb should be looked into. Might need a rebuild, but might just be an adjustment. I'd start by turning in the idle air mixture screws all the way to lightly bottom. Count the turns as you go, and then back them out to where they were. Often they get junk in the port, and this will sometimes clear it.
Once you've doen this, then start the car and turn the screws to see if you can get it to idle better. A half turn either direction, and then see if it idles up, or down. If it goes lower, then go the other direction. Repeat with both screws until it either improves, or doesn't; which means it needs a rebuld.
You may have to adjust the main idle screw up to start with if it wont stay running while you adjust the mixture. Once your're done and it idles at peak, then you can lower it to the proper neutral idle speed.

 

Being it's an 81,it was the first year they did the computer control on these cars,which added a few solenoids and switches on the carb.I'm not positive,but i believe when i had my 81,i dont think it had the manual mixture screws,as the mixture was changed by the computer,so it may be that the 30+ year old computer is malfunctioning,or not sure if it would cause it or not,but the 02 sensor could have went bad also.

 

I'm fairly positive the 80-81's didnt get an O2 sensor. While your car does have a QJet on it I can tell the PO pulled it out to paint the engine and who knows what he swapped. I see there isnt a mechanical fan either. That and the air cleaner say someone did a little work to it. The gold paint is weird though. It would have been blue from the factory.

From what I can seen in the pic. It looks like there arent any wires going to the carb, so the 81 "computer" is not running that. It may still be hooked to the dizzy but I doubt it. It looks as if someone got rid of the dumb stuff and left what was needed to function. They did a clean job from what I can tell too. I see a aluminum intake too.

The best way hands down to tune it will be an aftermarket A/F gauge and a O2 sensor in the exhaust. This can be done for less than $200 and that will tell you exactly what is happening. This is the easiest route. If you can tune with a vacuum gauge then by all means have at it. Otherwise there is a way to install the O2 sensor without welding.

You say it needs a valve job? Does it need just seals or a valve job? I wouldnt bother tuning it up if it needed torn down anyhow. I am NOT good with QJets. I can rebuild them but they never run the way I intend. They are also prone to throttle shaft leaks and about 25 other common issues. Awesome carbs when tuned right. I want to say that that is a BOP carb as well. The Chevy carbs had the fuel line come out the passenger side. OR vise versa. I toss them and will use anything but them.

Welcome, the car looks great. Start a build thread and we'll walk you through this.

 

Thanks very much to everyone for their advice. I will start by trying to identify the carb and then see if I can adjust it. If that doesn't work I'll order a rebuild kit for it. The previous owner did do some work to the engine so it's possible its not even a stock carb. The v-6 was bored and rebuilt at one point and yes they did do a good clean job from what I can tell.

As for the valve job I haven't gotten that far yet, just know that it will require seals or a valve job in the near future. It seems to hold good oil pressure and isn't burning a ton of oil so I'd like to just get it running right before tearing into the motor, unless I end up needing to tear into it to get it running right. Pretty sure it's just a carb issue and thought maybe there were some common problems with the carbs on this motor so that's why I asked for assistance.

Once I identify the carb and see if I can adjust it I'll update this thread. Thanks again for all of the advice.

 

It IS a stock carb. That much anyone can see. Its a Qjet. Pull the numbers and the rebuild kits are all the same. It may have sealed mixture screws but I doubt it. I would try adjusting it for highest vacuum. Or do what Val (1971BB427) said. It ran good once the way it sits. I havent seen bad seals keep a motor from running.

 

Post a closer up pic of the carb, with the air cleaner off. If yours is the ECM type, it would have a plastic connector for the fuel mixture control solenoid in the top, towards the front passenger side corner.

 

Thanks again guys for the responses. Here's some pics of the carb: