I just bought an 82 Z28 with a pos q-jet carb. Some days it will start up and idle fine, and some days it won't idle or run on all cylinders and when I turn it off, it has run-on for a second. I really want to save money and keep the q-jet, but is there another carb out there that I can get cheap that performs well and is not a pig on fuel?

Also, everything has been redone on my 91,000 KM original engine (tune-up), even a carb rebuild kit. Its just down to the carb problem, and then it should run mint.

Thanks in advance......

 

Check the choke vacuum break diaphram for proper function.
The choke will not function right without it.
Check the Anti dieseling solenoid on the throttle linkage.
It allows the throttle to close when you turn the key off,
preventing "run-on".