how can i lean out my 4bbl quadrajet? it is computer controlled. i know on edelbrock carburetors there are small screws in the front that can be adjusted. my 305 camaro runs extremely rich, when i get 3/4 pedal i get a wicked heavy smell of gas in the cockpit.

can i let the car idle, and lean it out, or will that screw up the ecm?

how exactly do i go about leaning it out?

is there any way without an air/fuel gauge that i can notice if i am running right? does my car require a wide band gauge or...

 

The are for the IDLE mixture. They are not connected in any manner way shape or form with whatever happens atMost likely, your secondary air valve is stuck, binding, not opening smoothly like it should, or misadjusted. Check that first.

The spring tension adjustment for a 305 should usually be about ¾ turn or maybe a bit more, but not over 1 full turn. If it needs to be outside that range for best A/F ratio, then it probably needs different metering parts.

If it's rich at idle, it most likely needs the metering well plugs fixed. They are in the bottom of the carb, where the factory drilled large holes in the casting in order to drill the smaller metering orifices through, and install verious small parts; and have fuel on one side and intake vacuum on the other. They are a different metal from the chinesium that the carb is cast from, and the carb material suffers from "dissimilar metal electrolysis" which erodes the casting over time. Nearly all Q-Jets eventually develop this problem. A leak there sucks fuel right straight out of the fuel bowl and into the intake, bypassing all carb controls entrely. Again, this will NOT cause a problem at heavy throttle, because vacuum is low (not much suction) under those conditions; this problem is worst at idle.

It also sounds like you have a serious exhaust leak. Verify that your exhaust system is intact and leak-free all the way to the tailpipes, which should NOT end before they reach the rear bumper.

 

damn, should i just replace the carb?

 

Probably not.

Is your SES light coming on? Does your SES light work?

How old is your O2 sensor?

 

ses light comes on when driving for 10+ mins on the highway, o2 sensor is probably 21 years old or so

 

Pull your codes?

 

how do i get the codes

 

https://www.thirdgen.org/service-eng...ht-error-codes

You've likely got some sensor that's malfunctioning and your ecm is staying in closed loop/warm-up mode which is full-rich.

 

Uhhh, staying in "open" loop.

 

k i will check em out

 

'Open' / 'Closed' :I've always had trouble with that as it's counter-intuitive to some of the schooling I've had. Let's say: 'non-feedback mode'