idle bouncing between 500-1000

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Jan 31, 2010 | 04:31 PM

Auburnbull

Thread Starter

Cruising

Joined: Apr 2008

Posts: 12

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From: Lemoore Ca

idle bouncing between 500-1000

A couple of weeks ago I ran very low on fuel before filling up. Since then I've noticed that my idle is much rougher than usual. It has a cam and has always had a good lope but now seems like it just won't hold a good idle. I've tried replacing the fuel filter, retune the computer, and gm idle relearn. I checked the vacuum hoses i see but am fairly new to ls1's. After about 1500rpm the car runs great which makes me think it is vacuum related. Does anybody have good vacuum hose pictures so I know where to look? Or maybe any tips in general on what's wrong.

Thank you.

Jan 31, 2010 | 04:45 PM

Blown 346

Melting Slicks

Joined: Sep 2006

Posts: 2,041

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From: Rockford Illinois

What size is your cam? with cold startups in cold weather its not un common for a you to get cam surge. I have it in my car and my cam isnt very large at all. 222/222Dur Lift563/563 on a 114 LSA. It can take a a fe wminuted for the car to learn where the cam is at for it to settle down.

Check behind the intake manifold there are a few vacuum hoses back there..

Jan 31, 2010 | 04:56 PM

0HorsePowerAddicts

Former Vendor

Joined: Dec 2009

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From: 19804

Hows the spark plugs look? Throwing any codes?

Jan 31, 2010 | 07:14 PM

ALLEGRO

Le Mans Master

Joined: Feb 2003

Posts: 6,683

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From: Memphis Tennessee

It makes a mess, but get some WD 40 and spray around each vacuum line one at a time. If you get a change in the idle, you have found a leak.

Good Luck

Jan 31, 2010 | 09:12 PM

dgrant3830

Tech Contributor

Joined: Dec 2006

Posts: 10,962

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From: Van Buren Arkansas

Wounded Warrior Escort '11

As mentioned, codes, vacuum leaks, air-bridge leak. You might want to check out your pcv valve and its connection tube to the intake as well.

Feb 1, 2010 | 12:23 PM

BLOWNBLUEZ06

Tech Contributor

Joined: Apr 2007

Posts: 10,924

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From: Forney Texas

Quote:

Originally Posted by ALLEGRO

It makes a mess, but get some WD 40 and spray around each vacuum line one at a time. If you get a change in the idle, you have found a leak.

Good Luck

Or if you don't want the mess, use a Propane torch without igniting it and run the propane around the possible leaky areas.