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View Full Version : Help! Carb Vapor lock


WBowie
07-08-2005, 08:59:00 AM
Ok My car is fine in the morning but as the engine warms up to operating temp I end up having to use my left foot for braking and my right foot on the gas to keep the engine from shutting off. I have a Holley carb on an Edelbrock performer intake, using a metal fuel line. Is it just running too lean?

Mwilson
07-08-2005, 09:14:00 AM
Is this something it just started doing or has always done with this carb?
Could be some simple trash in the Idle air bleeds or something.

BluEyes
07-08-2005, 11:12:00 AM
does it run fine aside from the two-footing?
It sounds like you need to up your idle speed screw. The fast idle cam is probably keeping the carb happy when the engine is cold.
I'm assuming you have an automatic? You need to have it in drive when you set the idle speed. Either securely chock it, or borrow a friends foot...

Joekool
07-08-2005, 09:24:00 PM
Your symptoms dont sound like vapor lock, vapor lock makes the engine stall and then when you try to restart it it feels like it is out of gas.

WBowie
07-08-2005, 11:01:00 PM
Right. After it stalls I have to pump the gas pedal once or twice to get it started again.

Joekool
07-09-2005, 01:19:00 AM
Yes but with vapor lock the engine will not restart like it is out of gas until the fuel cools off. Vapor lock is caused by fuel boiling inside either the float bowl or the fuel line, once the fuel boils the pump can not pump it (fuel pumps have a hard time pumping a gas) and the engine stalls. Once the fuel cools to below the boiling point and becomes a liquid agian then the engine will start.

What your symptoms sound like is either too low of an idle speed or a really lean idle or really rich idle. Do you see any smoke, smell any fumes or notice anything else coming from the exhaust? How does the engine run otherwise?

zbugger
07-09-2005, 10:59:00 PM
This also sounds like what happens when you have a bad pcv valve. If you're running one, check it out.