Carb Issues
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Junior Member
Joined: Mar 2017
Posts: 3
Likes: 0
Carb Issues
I have recently purchased a 85 Z28 with a 350 engine swap. It had a 750 carb on it but it was to much and couldn't get the idle down. I have a holley 600 CFM carb with electric choke. When I put the carb on my engine, it idles at 3,000 rpms. I have checked for vacuum leaks and have found none. When I open the choke flap fully open, I can get it to idle normal. If I rig the flap open it is good, but I want to know why! I know that is not right and I want to know how to fix this the right way. Anyone know about this?
Member
Joined: Apr 2015
Posts: 467
Likes: 8
From: Waldron Arkansas
Car: 1986 IROC Z28
Engine: Carburated small block 454
Transmission: Level 3 Raptor 700R4 2600 stall
Axle/Gears: Strange S60 3:73 S Trac Posi
Re: Carb Issues
Sounds like you need to adjust the electric choke; what 600cfm carb are you running?
Member
Joined: Dec 2016
Posts: 187
Likes: 2
From: Sebastian FL
Car: 87 firebird 86 c10 90 mustang
Engine: 383 sbc
Transmission: 97 t56
Axle/Gears: Moser 12 bolt 3.73
Re: Carb Issues
If you don't have power to the choke or don't want to run power if it's not there you can loosen the 3 screws on the choke and turn the plastic part. That will turn it off mechanically for good.
Member
Joined: Apr 2015
Posts: 467
Likes: 8
From: Waldron Arkansas
Car: 1986 IROC Z28
Engine: Carburated small block 454
Transmission: Level 3 Raptor 700R4 2600 stall
Axle/Gears: Strange S60 3:73 S Trac Posi
Senior Member
Joined: Feb 2008
Posts: 706
Likes: 0
From: Central PA
Car: 1990 IROC
Engine: Rebuilt L98 with H/C/I/Carb
Transmission: TH350 with ATI Treemaster
Axle/Gears: 7.5 with 4.10's
Re: Carb Issues
You had a 750 on it, and you couldn't get the idle down. Then you put a 600 on it and can't get the idle down. I am guessing it is not the choke. Check the basics: Is the throttle cable holding the throttle blades open (and off the idle adjusting screw)? What is the base timing advance at idle (with vacuum advance hooked up)?