fuel problem

[ogier]

have an 86 camaro with a 305 carb motor all computer controlled need info on how to lean out fuel to air ratio

[MagicRat]

I seem to recall these carbs received an electrical signal from the ECM which adjusted a needle and seat arrangement inside the carb. This adjustment had a limited influence on mixture.

If you wish to have a manual mixture adjustment, it may be reasonable to bypass the ECM input into the carb and use a variable resistor to provide an adjustable voltage input into this mechanism (presuming the 22 year old carb is still functioning correctly).

Alternately, go for a tuneable aftermarket spreadbore carb, like an Edelbrock (carter) or a Holley, and learn how to jet it properly.

[UncleBob]

create a vacuum leak

might help if you offer a bit of info. Is it running rich? trying to pass emissions? Trying to improve economy? details are aways helpful

[J-Ri]

The computer controlled carburetors use the needle valve for controling fuel into the engine, the total amount of fuel, not just the mix. (all they are is a fuel injector without a nozzle built into a carburetor body) If you use a variable resistor, you will be able to control how much fuel the engine gets (although it should have an on-off pulse or the winding could/will burn up), but it would mean turning it while you accelerate and when the trans shifts, more work than what I would want to do. At the same time, if it does have the CCC, it will also have an O2 sensor which would mean the vacuum leak wouldn't help either.

If it's a non-CCC, then do the vacuum leak. "T" into the brake booster hose and run it to a valve inside the cab, and run the other side of the valve to the air cleaner. That way you can control the leak for when you want more fuel.