71 Cutlass Supreme Convertible 455 W/650 cfm Carter carb.

Having a fuel issue. After I drive about 2 miles above 45 miles per hour the engine starts to bog and then dies. Stop and sit for 2 mins car will restart idle fine take off again then about a mile further same thing like its running out of gas? If I am driving at low speeds it will stay running but stumbles from time to time. I have a glass inline filter when the engine dies the fuel is bubbling in the filter with a big pocke of air in it. Once I restart the filter fills with fuel. The fuel pump looks pretty new and has the return blocked off, I assumed that this was done because the car didnt have a return line and the new pup did. Now I check it out and it does have the return line and it is blocked off also. I guess I need to connect it? Could this cause my problem? Is there any reason someone would block the return line?

 

Yes the fuel return is to prevent vapor lock. I would hook it back up.

Welcome to the forum.

 

Took the car out today 90 degrees here in Chicago, ran like crap again. I picked up some fuel line rerouted the pressure line from the pump to make sure it isnt touching the engine. I ran a new line from the pump to the return line went for a drive, ran worse than before. I got about 2 blocks car died and I could hardly get it to idle now. I could smell gas so I looked under the car and there was a big puddle under the fuel tank. Looks like whoever put the new tank in before I got it never hooked up the line at that end. I plugged the line at the pump and the car runs just like it used to. Should I be able to run with this return line plugged? It seems to me that some older pumps didnt even have a return line. Please help beutiful convertible weather and I cant cruise!

 

Get that return line in operating condition. That was what they put it there for-to solve just the problem you are experiencing.

 

Back at it today. I hooked up the return line again and got underneath the back end to see where the fuel was leaking from, it was coming from one of the vent hoses! I couldnt make sense of the lines under there so I got out my chassis manual. From the diagrams in the book some cars had return lines and some didnt. Mine doesnt have one that extra line up front is the emmisions line to the canister that is missing on my car. So back to square one replugged the return port on the pump The car wasnt overheating but I thought it was running a little hot (no gauges on this one just idiot lights). I didnt know what temp the T-stat was so I picked up a 160 degree and put it in. Ran the car like this no problem runs perfect but it is about 20 degrees cooler here today. The stat I pulled out is stamped 160 so either it wasnt opening all the way allowing the motor to run to hot or just the cooler weather is fooling me. Have to wait for the next heat wave and see.