No Idle

[basement]

360ci, Edelbrock 650 carb, Electronic Ignition.

The engine will not idle unless I open the throttle to about 1500rpm. Anything above 1500rpm and the motor performs well but the moment I let off the throttle to allow the engine to run on Idle circuit then it dies instantly.

I have done no mods to the engine/carb, this symptom came on quite suddenly. I've tried a new fuel filter/fuel pump/adjusted the idle mixture screws but nothing seems to help. I've pulled the plugs and they appear on the lean side.

I plan on removing the gas from the tank and starting with new, this gas is probably a year old. Any other suggestions would be appreciated.

Thanks

[Super Blue 72]

Try checking to see if you have any cracked vacuum lines. 

Might be worth a shot to poke around the vacuul lines.  My car had similar issues, wouldn't idle, had to keep my foot on the gas.  Found that a vacuum line on the back of the carb that had to make a bend was the culprit, cracked at the bend.  Changed it out and all was good. 

[Strawdawg]

Unlikely it is the gas.  Assuming the bowl is at the proper fuel level,

I would look for a vacuum leak and then an internal carb problem.

[Skunkworks Challenger]

I would disassemble the carb and rod out the jets in the idle circuit.  If the problem came on suddenly I think it indicates something plugging the idle circuit.  PK

[Chryco Psycho]

I agree that something is wrong in the idle circuit , try removing the idle mixture screws & blowing compressd air or carb cleaner through there , then reset the mixture screws for best idle

[mopar12372]

check for a vaccuum leak.     may be the vaccuum buster hose is rotton and leaking .      pcv valve hose leaking.

intake manifold leak vaccuum lines leaking disconected  . is the distributer tight ? did it move ? is there enough fuel to run the engine?


is the float level too high?  some simple ares to check to give you an idea .

[WildJones]

I had an issue like this that suddenly arose last week. Ended up being ignition module in the distributor. First the car went from not wanting to idle to not starting at all (no spark). Before I lost spark I tried playing with the carb, then had my mechanic buddy play with the carb, but neither of us had any luck. Then when I wasn't getting any spark another friend tracked down the issue to the igniton module (running a Mallory distributor). After replacing the module she sure runs better than she has in the last few years  . Sounds like your car has been sitting though, I have been driving mine regularly to and from work so I guess this probably won't help you any.

[Bullitt-]

I recently had what sounds like the same thing.   Found a vacuum leak at the PVC hose. 

[Chryco Psycho]

it can leak into the brake booster as well so try disconnecting the brake booster hose

[footin70rt]

Several years ago the AFB on my Dart did the same thing, runs good off idle but as soon as the throttle blades closed it would die. Ended up being the idle circuit of the carb. I tried blowing out through the idle mixture screws and got one side cleaned, then would try to idle on four cylinders.  Ended up having to take the carb apart and soak it to get the other side cleaned out.