Idle problems
Thread Starter
Cruising
Joined: Dec 2007
Posts: 12
Likes: 0
From: Maryland
Idle problems
My vette wont idle when its warm. It konks out at stop signs unless I keep my on the gas. The problem seems to be getting worse with time. It idles fine when cold.
Its a 71 LT1 with wih a Holly carb. Any ideas?
thanks
Its a 71 LT1 with wih a Holly carb. Any ideas?
thanks
Le Mans Master
Joined: Jan 2004
Posts: 8,295
Likes: 30
From: one night in Bangkok you are never lonely
Sounds like vapor lock. Are you running a return line from the fuel pump to the tank? The return line keeps the fuel flowing and cool so there is no boiling in the line. I even run an in tank fuel pump and a return line from the carb to the tank. Over here the traffic lights are long and temps are always over 95* during the days. With out the above the idle will drop to stall at lights.
Le Mans Master
Joined: Jan 2004
Posts: 8,295
Likes: 30
From: one night in Bangkok you are never lonely
The OP says the problem on hot days is at stopping so I assume his idle is OK when moving. Been there done that.
Race Director
Joined: Oct 2000
Posts: 15,036
Likes: 79
From: central FL, near the beach.
posters are notorious for poorly describing things, however
Le Mans Master
Joined: Jan 2004
Posts: 8,295
Likes: 30
From: one night in Bangkok you are never lonely
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Pro
Joined: Nov 2004
Posts: 575
Likes: 0
From: Nice Lake Ontario
If car is moving I sincerely doubt it's idleing
He said "won't idle when warm", I assume he meant when warmed up & choke kicked off.
Tech Contributor
Joined: Aug 1999
Posts: 14,379
Likes: 6,390
From: At my Bar drinking and wrenching in Lafayette Colorado
If idle quality is bad or erratic on a hot Holley, check for a warped metering block. A non-flat block will allow fuel crossover between idle and main circuit metering passages, and will cause the problems you describe. Just lay a straight edge across the block after you remove it from the carb and verify that it is flat within .005" in every direction and on both sides. If it's warped, just get a new one from Holley - a very affordable fix that will make a huge difference in idle quality.
Lars
Lars
Thread Starter
Cruising
Joined: Dec 2007
Posts: 12
Likes: 0
From: Maryland
To clairfy: Engine won't idle when it has warmed up. Choke - as it should - gradually opens as engine warms. The engine will continue to idle when warm until the first time I rev it. After I rev the engine - and the choke kicks off - the engine won't idle.
The car will restart after cutting out - but only if I keep my foot on the gas giving it some revs (it will idle at 700 to 750 - maybe as low as 650 while giving it gas). When I stop giving it revs it konks back out.
I will definitly check level of metering block. If level I will clean it.
thanks to all - this is a really big help
The car will restart after cutting out - but only if I keep my foot on the gas giving it some revs (it will idle at 700 to 750 - maybe as low as 650 while giving it gas). When I stop giving it revs it konks back out.
I will definitly check level of metering block. If level I will clean it.
thanks to all - this is a really big help
I'm a genius 