quadrajet was running rich,took it apart clean it and adjusted the rich mixing stop screw. now the idle is mested up turned idle screw all the way back sill at 1500-2000 rpm. help!

 

What year of Q jet is it? stock? Computer controlled? get the numbers off the side should be something like 1708XXXX. All of this info will assist in diagnosing your issue.

 

carb#17085204, 0355 hzj 1985 stock computer controled

 

If it was running rich from the start and now it is worse I would start by replacing the float, needle and seat. The float may have been saturated, and or a worn needle valve, will cause a too much fuel. The computer will allow more air in to match the fuel and it will rev higher. If that doesn't help it may be an electronic issue, with the TPS, computer, or the mixture control solenoid.

Here is an interesting link with similar issues to yours....
http://www.carkb.com/Uwe/Forum.aspx/...runs-VERY-rich

 

The computer doesn't have any control of the air flow.

 

Correct ! What I meant or should have said is "with the additional fuel possibly caused by an electronic issue...high engine speeds RPM result"

Thanks for the correction. Sometimes my mind gets ahead of myself

 

it starts up ok the choke kicks on and off like it should. but after the motor warms up the isc (idle speed control ) kicks in and speeds up the idle. if i disconect this wire to the isc it kicks off and runs ok.

 

Idle speed control? This must not be a 3rd gen f-body.

 

after taking the carb apart again rechecking the rich mixing screw and the lean mixing screw checked the float levelruns good has more power now. but the check engine light comes on not every time

 

OK, so what code is it throwing at you?

How exactly did you check the rich and lean adjustments?

 

Do you mean the idle bump solenoid (idle load compensator)? It's intended to increase the idle when the AC is on or as commanded by the ECM-such as when the ESC wire is disconnected from the dist.

What codes?

 

yes that sounds like what i meant to call it ( idle speed compensator ) it not sending a code its the check engine light will come on. not every time i drive the car.

 

Check the codes. It will store them even if the light is not currently lit.

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