Thread: wont idle all of a sudden

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the cars running perfect yesterday, today i start it and it wont idle took it around the block it sounds like its loading up till you just touch the gas and then it wonts to throw you back in the seat, what happened i checked the float levels and fuel just at the bottom of the sight holes.

Vacuum leak, maybe..........

also before after she was warm you just turn the key and shed fire right up now you can turn the key as long as you want and she wont start looks to me like im giving quarter throttle to keep it running and if you ring the throttle down a bit sounds like shes running on seven cylinders, i checked all hose connections every things still the way it was i havent touched anything on the motor except for cleaning

Cleaning?? With water? Did you spray it? I that's all you did, I would look for wet wires or distributor.

Yup. that could be. Check for moisture under the dist. cap.

no water just a dry towel why do i have to pump the gas one time when shes warm and i never did before im going nuts guys, i have three car shows this weekend help

i respect all you guys help. im going to call holly tech line tomarrow , i think somethings restricting fuel at idle, if some ones had a simular problem and found the problem please let me know..thanks

If it's not water,,,,,, if it wants to die at idle, but runs when you give it gas, i'd say check for vacuum leak. Maybe a vac hose cracked or got pulled off ?? It's the easiest thing to rule out first. Spray some ether around suspect areas while it's running. If there's a leak the rpm will change when you spray it.

Might be dirt in the carb (Like the idle circut maybe) hard to tell with a keyboard.

Originally Posted by pro70z28

If it's not water,,,,,, if it wants to die at idle, but runs when you give it gas, i'd say check for vacuum leak. Maybe a vac hose cracked or got pulled off ?? It's the easiest thing to rule out first. Spray some ether around suspect areas while it's running. If there's a leak the rpm will change when you spray it.

Might be dirt in the carb (Like the idle circut maybe) hard to tell with a keyboard.

i diagnose cars all the time with a keyboard at work.... then again they're on the smog machine

First thing I'd check is the power valve.

Maybe a bad or loose plug wire??? Like Pro said, kinda hard to tell with just a keyboard. Whatever you find out, please let us know.

Good Luck,
Dutch

ill do the ether check, and anything else i can , ill let yas no , thanks everyone

what is the purpose of the power valve? how do you know if its bad? im not sure

Originally Posted by S19243H

what is the purpose of the power valve? how do you know if its bad? im not sure

The power valve is simply a "switch" that opens at a predetermined manifold vacuum, measured in inches of mercury (Hg). A vacuum passage in the throttle body transmits manifold vacuum to a chamber in the main body. When manifold vacuum drops, a spring opens a power valve in this chamber to admit extra fuel. This fuel flows through the power valve, through the power-valve channel restriction and into the main well. There it joins the fuel flow in the main metering system to enrich the mixture.
If the power valve is blown it can result in a very rich condition at idle.
Most of this information came from the Holley Carburetir Handbook by Mike Urich. If you're going to work on a Holley I highly suggest you get a copy of this book or one like it.

This is the book I'm refering to.