Qjet running A little rich

My car is running rich,I need some help adjusting it.If some one could give me some advice, I would appreciate it.

 

A good start is to turn both mixture screws all the way in, then back them out 2 1/2 turns each. Fine tune from there.

 

I have A dwell ,RPM meter,would that be A good tool,fine tune with.

 

^^^ Yep.

Vacuum gage and tach.

(start with warmed up and choke off)

Adjust to the highest vacuum and RPM to about 850, with both the idle screws/circuits balanced (same turns).

I usually lightly seat both, then back out both 1 and 1/2 turns, then start the car.

Get the idle with set screw to 850 then turn one screw out 1/2 turn then the other and observe the vacuum gage.

I do this until the turns affect the vacuum fall off then start 1/4 turns.

Sometimes the idle set screw needs to be adjusted to keep in the 850 range.

Once everything is smooth and highest vacuum, set the idle screw to the appropriate RPM for auto or standard.

Then "blip" the throttle a few times. And see if it settles where it needs to be.

Then pull and plug the vacuum advance to intake, and check the timing. Reconnect the line.

Take out and drive and see how it runs, then next time you have gone from a cold start to warm up, you can connect the vacuum gage and see if the settings are still holding.

If you have a performance cam, you may have to have a higher RPM 1100 or more to get a smooth idle and steady vacuum, then you can set the idle set screw to bring the RPM where it needs to be after the setting the idle circuits.

 

OK thanks guys
I have A vac gauge,were is the best port to hook it to.

 

Direct manifold (not ported from carb or accessories).

 

If an auto trans car, I hook up to the trans modulator line coming out of the back of the intake.

 

Ok,thanks for the help, I appreciate it.

 

I just wanted to thank y'all guys for the help. I adjusted my carb to get the highest reading on vac gauge .It's A lot better now.I pulled A plug first ,and it was black,after adjusting carb and running it for awhile, pulled same spark plug ,and the tip was turning brown,the way it should .

Thanks for the help guys, I very much appreciate it.

 

If you want to keep it sharply tuned then in 2 months when night time temps do not go below 55 degrees any more readjust your hot idle mixture again.

 

ok thanks
I will do that.

 

I had previously adjusted my quadrajet for Max vacuum at idle but was still having a bog off the line. Went through and followed your instructions and whamo it runs perfectly.
Thanks

 

I adjusted my carb, like TrunkMonkey said, and it ran very good.It was running rich, but now plugs Are brown not black like before .

 

BTW - before you monkey with the idle mixture screws look around for vacuum leaks. If you have one you might well find the mixture screws have little to no effect on idle speed (speaking from experience here).