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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: VeeTwin60 on April 18, 2010, 05:44:33 pm

Title: EXTREMELY High Idle - Edelbrock Carb
Post by: VeeTwin60 on April 18, 2010, 05:44:33 pm: Hi Guys - I've got an #1406 Edelbrock carb (electric choke) that I just bought and installed. It is on an '86 Custom Deluxe with a 350 cu.in. and TH350 trans.

After the install, I started it for the first time and the idle is around 3500 RPM. I cannot figure out why. I've disconnected the throttle and kickdown cables. I've backed the idle adj screw all the way out. I've made sure no linkage is stuck. I've manually opened the choke butterfly plate. Nothing works. Please help!
Title: Re: EXTREMELY High Idle - Edelbrock Carb
Post by: VileZambonie on April 18, 2010, 06:13:06 pm: Did you hook up the brake booster hose to the back of the carb or at least plug that port?
Title: Re: EXTREMELY High Idle - Edelbrock Carb
Post by: HAULIN IT on April 18, 2010, 09:09:24 pm: What intake is on the engine...Spread bore flange? Lorne
Title: Re: EXTREMELY High Idle - Edelbrock Carb
Post by: Blazin on April 18, 2010, 09:39:30 pm: Edeljunk! Thats why!
Title: Re: EXTREMELY High Idle - Edelbrock Carb
Post by: Irish_Alley on April 19, 2010, 01:38:56 am: like vile said sound like a vacuum leak
Title: Re: EXTREMELY High Idle - Edelbrock Carb
Post by: VeeTwin60 on April 19, 2010, 04:09:46 am: I've hooked up the brake booster to the back port. I've got the PCV valve to the front port. I've got the distributor/trans hooked up to the driver side 3/16" port, and plugged the other 3/16" port.
Title: Re: EXTREMELY High Idle - Edelbrock Carb
Post by: Irish_Alley on April 19, 2010, 05:11:06 am: check your seal between the carb and intake
Title: Re: EXTREMELY High Idle - Edelbrock Carb
Post by: greenmonster on April 19, 2010, 05:48:05 am: Did you check the fast idle screw.
Title: Re: EXTREMELY High Idle - Edelbrock Carb
Post by: VeeTwin60 on April 19, 2010, 08:02:27 pm: Quote from: greenmonster on April 19, 2010, 05:48:05 am
Did you check the fast idle screw.
How embarrassing. I didn't even think about that. Thanks.
Title: Re: EXTREMELY High Idle - Edelbrock Carb
Post by: HAULIN IT on April 19, 2010, 09:15:26 pm: Quote from: HAULIN IT on April 18, 2010, 09:09:24 pm
What intake is on the engine...Spread bore flange? Lorne
I just checked in to see how you've made out & noticed you haven't answered this. Do you have a spread bore (q-jet) type intake or a square flange (Holley) type?
Title: Re: EXTREMELY High Idle - Edelbrock Carb
Post by: beastie_3 on April 20, 2010, 01:37:22 pm: I believe you can download the tuning instructions directly from Edelbrock also.
Title: Re: EXTREMELY High Idle - Edelbrock Carb
Post by: VeeTwin60 on April 20, 2010, 06:25:49 pm: Quote from: HAULIN IT on April 19, 2010, 09:15:26 pm
Quote from: HAULIN IT on April 18, 2010, 09:09:24 pm
What intake is on the engine...Spread bore flange? Lorne
I just checked in to see how you've made out & noticed you haven't answered this. Do you have a spread bore (q-jet) type intake or a square flange (Holley) type?
Square.
Title: Re: EXTREMELY High Idle - Edelbrock Carb
Post by: HAULIN IT on April 20, 2010, 10:44:14 pm: What type of carb did you have on it before this install? Studs or bolts just a hair too long (running out of threads)? Did you move or change anything like accessory brackets or anything else that bolted to the intake while you were doing the carb swap? I agree with the others...likely your hunting a vacuum (air) leak. Lorne
Title: Re: EXTREMELY High Idle - Edelbrock Carb
Post by: VeeTwin60 on April 22, 2010, 06:56:09 pm: It was the fast idle screw. Look a few posts up. :)
Title: Re: EXTREMELY High Idle - Edelbrock Carb
Post by: VileZambonie on April 22, 2010, 10:40:50 pm: when the choke is open you should be off of the fast idle cam. You may want to double check it's operation.