Fuel System: 64 Avanti Runs, after 5 minutes stalls

[Ted Johnson]

My 64 Avanti R1 will start, idle for minutes in the garage, then when taking out on the road runs for 5 minutes, then stalls. It will often re-start and run with starting fluid down the carburetor. A shop recently replaced fuel filter and fuel pump. Could it be vapor lock? Fuel line is insulated. What causes this? Regulator and coil are new. Any ideas? I had the car in a shop for three months and the pump and filter were there solutions, also installing a stronger ground connection. It did run fine some 20 miles home from the service garage, though! She has been burning ethanol gas, but I am going to transition to non-ethanol next tankful.

[PackardV8]

Always confirm you have a vented gas filler cap and that the vent is open.

jack vines

[jts359]

Here are a couple of thoughts , A Rust hole in fuel line causing air to get in and the pump won't pump, Something clogging the fuel line from inside the gas tank , Have the rubber fuel hoses been replaced. Maybe they are collapsing under vacuum Do you have spark when this happens ? My R-1 Avanti has never had a vapor lock issue , I wish I could say that for my Daytona , Ed

[Ron Strasser]

Ted;
Drive the car until it stops. Remove the air cleaner and look into the carburetor while opening the throttle. You should see gas. If you don',t you have a fuel problem If you do the problems is most likely someplace else.. Next check for spark. If the Avanti's return fuel line is intact it should not vapor lock.
Ron

[landriopa]

In 1985 as I was starting up the Allegheny Railroad I bought a very used 78 Dodge railroad pickup truck from the Bessemer Railroad in Greenville, PA. I drove it five miles to I-79 and she died. After an hour she would start, drive about five miles and die again. Had it towed to Erie and a garage changed the fuel pump, the gas filter, flushed out the gas tank and lines and rebuilt the carburetor, over $300 of work. I picked it up drove five miles and it died again. This story was many years ago submitted to Car Talk on NPR.

The problem was that there is a fuel line of rubber between the fuel pump and the metal fuel lines running up from the tank. The rubber was so old that when it got warm from the engine it would lose strength and collapse. It would take about five miles for the engine compartment to heat up enough for the rubber to be affected. Less than a dollar of hose it was fixed!