i just put a new q-jet on my 85 firebird t/a and its idiling high and diseling, is there a vacume line i could of forgot becouse i dont see any..and other possibles, it runs fine just dont want to turn off
thanks

 

First, make sure your choke is opening completely.

If it is, then turn the idle speed down.

 

i have done that but its still doing it
thanks

 

did you bump the Disributor so it is very advanced?
Try turning the distributor clockwise a little so the idle drops off abit, then see if it is still doing it. If you got a timing light that will make it heaps easer.

 

The high idle speed is most likly the cause of the run on.

diseling is norm cased by the throttle plates (butterflys) being opened too far at idle and letting enough air enter the car so it keeps running.

Being a new q jet, I would say the idle speed is not 'pre set' at the factory.. Just adjust the idle speed screw down till you have it at about 650-700 RPM idle speed in park.

That should take care of the run on..

If it don't look for other things that may be holding the throttle plates open.. Like a throttle return spring thats too weak to close the throttle all the way against the stop.

 

Is your new CCC Q-Jet carb the elect. stock carb that is for your 85 T/A????

Auggie

 

Diseling is caused by a high idle, carbon build up in the combustion chamber, the car is running really hot, the choke plates not opening all the way or the timing chain is bad. I had the same issue and I changed the idle and flushed the engine with some sea foam (engine cleaner) never had a problem since.