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Engine will not idle below 950rpm

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Engine will not idle below 950rpm

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Old

Feb 12, 2017 | 10:08 PM

#1

Justin73supercamper

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Tuned

Joined: May 2016

Posts: 448

Likes: 13

Engine will not idle below 950rpm

I have a weird problem. I have a 390 Holley 770 street avenger. A height distributor. I had a wood carb spacer that cracked I replaced it new base gaskets for the carburetor. My timing is at 11degrees base. It will not idle below 950 rpm. I disconnected my throttle linkage. Turned the base idle screw all the way out with not change.I cleaned the primary jets and looked for vacuum leaks. I'm using a digital timing light to set the idle and rpm. I'm out of ideas any body have any?

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Old

Feb 12, 2017 | 10:24 PM

#2

TheMonson

More Turbo

Joined: Oct 2014

Posts: 504

Likes: 4

From: Malheur County

Vacuum leak?

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Old

Feb 12, 2017 | 11:53 PM

#3

Grandad's Truck

New User

Joined: Feb 2017

Posts: 1

Likes: 0

Check to see if the valves on the bottom can't close all the way. If you don't have the Holley spacer and you are on the Edelbrock intake, the valves on the bottom can catch just enough to not close all the way.

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Old

Feb 13, 2017 | 01:36 AM

#4

meangreen92

Logistics Pro

Joined: Jul 2005

Posts: 4,217

Likes: 154

Check your secondary throttle blades and make sure they are closing. Sometimes they can get hung up for whatever reason, resulting in a high idle.

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Old

Feb 13, 2017 | 07:19 AM

#5

DB429SCJ

Laughing Gas

Joined: Apr 2016

Posts: 858

Likes: 118

From: Buffalo NY

Make sure the choke is all the way off and the fast idle cam is all the way down.

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