carb problem?
02-08-2014, 02:02 PM
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carb problem?
Don't know if this is a carb problem but I'll pitch it out there. I recently bought an 83Z LG4 with a 4 barrel quadrajet carb. When I fire up the car, it jumps to 2300 to 2800 rpm and stays there. It never drops down to idle rpm. Is this a carb tune problem or something else?
02-09-2014, 06:00 PM
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Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Most likely it is something holding the throttle blades open. Could be the choke high idle cam (meaning the choke isn't disengaging the high idle cam for some reason), gummed up works, bad throttle cable, improper adjustment, etc.
02-10-2014, 11:18 AM
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Re: carb problem?
Thanks, I removed the carburetor and everything seems to be working ok mechanicaly but I have a question. Are the blades controlled by electronic sensors? How does it know when to idle down?
02-10-2014, 11:47 AM
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Re: carb problem?
Looks like the air valve spring adjuster.
this link has alot of info and diagrams on quadrojets
http://vetteworks.tripod.com/qjet.htm
this link has alot of info and diagrams on quadrojets
http://vetteworks.tripod.com/qjet.htm
02-10-2014, 01:37 PM
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Re: carb problem?
I'll check into that connection. Thanks. There are two electronic connections on the carb. I'm guessing one is for the choke but don't know what the other is.
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02-10-2014, 02:07 PM
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Car: 1987 SC/1985 TA
Engine: 350/vortec/fitech
Transmission: T56
Axle/Gears: 3.27 9-bolt
Re: carb problem?
02-10-2014, 04:37 PM
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Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Re: carb problem?
If that affects your idle when the engine warms up, for sure your choke isn't opening.
02-10-2014, 04:40 PM
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Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
There is no power wire connected to your choke thermostat. That wire provides 12 volts to the choke thermostat coil to warm it up so it opens the choke. Find that wire and hook it up. It's a single wire.
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