heres the scoop, my 50 shoebox, 56 265 powered, holly electric fuel pump mounted just forward of the tank on frame rail. Left exhaust about 2 inchs from the pump, 3/8's fuel line to the firewall, runs up behind left side of engine, clamped to inside valve cover bolts, turns 90 degrees to carb, 6 inch rubber line to carb.Craps out , pump the gas pedal, picks back up. Has always run fine untill we started getting 100 degree plus weather, could the fuel pump itself be vapor locking?
Could be. Best way by far to get rid of vapor lock is to have a fuel return line. Make one out of 1/4", tee it in at the carb. Constantly moving fuel stays cool.
put a heat shield between the pump and the exhaust. 2 inches is close fuel boils easily . air space is your friend , How is the fuel filter ? It also could be boiling in the carb at high temps a thicker base gasket may help or a gasket with a metal spacer and a gasket may help. how is your fuel pressure . I have had more than 1 Holley pump failure. Just wanted to offer up some ideas to get you headed down the road .
I had 3 Holley pumps before I gave up on them. Pressure variations all over the place, and then they just quit. Carter is the best I have found. The return line idea works well if heat is your problem.
A lowered car holds heat on the underside in this weather. A stock fuel pump often works better. I use a stock fuel pump with an electric for a booster when the car hasnt been run for two weeks, and when I race. I have a thin aluminum heat shield between the fuel line and the exhaust. No problems yet - - - -
My buddy had the same problem for years, he tried everthing, insulation, moving the fuel lines, etc. He has a 5.0 Mustang running gear, with the stock fuel injection. His system has a return line and it still did it on hot days. The problem was that his engine was shoehorned into the engine bay, and it built up a lot of heat on hot days. He finally installed a Mercedes Benz fuel line cooler. They have a cooler that splices into the fuel line and the other side splices into your air conditioning system (if you have one). It cured the problem. On hot days he turns on the air just enough to stop the vapor lock. Of coarse, you have to have AC. The bottom line is: you've got to cool down the fuel some how.
jaguar uses a similiar setup on the v12. varys on how it works. i dont think real uncommon on european cars
they do have those fuel cooler cans, you fill them up with ice to cool your fuel line. i had a buddy hook it up to his vacuum line, and wow the vacuum made the can really cold.
*copy* *paste* *save* in brilliant idea folder! Now I've got to hook up my A/C hose to my wife's pressure cooker and see if it affects the temperature inside. We now return you to your regularly scheduled thread...
The Jalopy Journal
