Expert: Ben Deutschman - 2/16/2008

Question
I have a 1979 plymouth volare,with a 225ci super six 2bbl the engine starts and runs at high idle but stalls when the choke is opened, it will stay running if i keep feathering the gas pedal,It stays the same in drive or park. thanks, john

Answer
The clue to me, is that your Volare runs with the Choke on. I would therefore assume that there is a vacuum leak somewhere. First, check ALL the Vacuum Lines going to the Carburetor, Manifold, and any other Lines that go into the car (most Heater Doors are vacuum operated). After you've eliminated those possible sources, the next step is to take a can of Carburetor Cleaner, and with the Engine running, CAREFULLY spray it at the Intake Runners where they meet the Cylinder Head. BE VERY CAREFUL when spraying the Carburetor Cleaner, it is flammable, but it's the only effective way to find a bad Intake Manifold Gasket. If there is a leak at any one of the Intake Runners where they meet the Cylinder Head, the Engine speed should change. Since you already have a Choke off stalling problem, I'd expect a slight increase in Engine speed, when the Cleaner is sprayed at a vacuum leak source. If the Manifold Gasket checks out, then you may have a bad Carburetor base Gasket, which can also be found by spraying Carburetor Cleaner carefully around the base of the Carburetor, where it meets the Intake. If all of those things check out, then the Carburetor itself may have an internal vacuum leak, and need to either be rebuilt, or replaced. It is highly doubtful that any of the chain Auto Parts Stores that now dominate the market, will have, or be able to get, a Carburetor for your car, so you will probably have to Google search Carburetor Rebuilders, and see what pops up.