Coming back from upholstery shop on a 105°+ day car felt like it was starving for fuel a couple of times, never had this problem when below a hundred OAT and my water temp. went to 205°, usually 185-190° max. I'm thinking vapor lock, have an electric fuel pump but only puts out 5lb. max; is this insufficient pressure to overcome vapor lock? Perhaps the somewhat close proximity of the fuel line to the head is causing the fuel to boil on extremely hot days? I could rotate the fuel line around to move it further above the head and or some type of insulation around fuel line between regulator and carb? Edelbrock recommends no more than 5.5lb. for their carb. My upholster told me back in the day they attached wooden clothes pins to the line.........like a heat sink? Any suggestions?
Where is the pump mounted? How close to exhaust is the fuel line? Carb is on backwards.... ...... Lol Sent from my LG-H343 using The H.A.M.B. mobile app
I had a Holley regulator on the firewall of my 48 Ford sedan. When the under hood temperature came up the fuel pressure would drop, until I began running out of fuel. I eliminated the fuel pressure regulator and installed a electric fuel pump that's rated 4-6 psi. No more problems...
Know of several people that had vapor lock problems last month in New Mexico. Some were running the after market EFI. Has to partly be caused by our crap gas.
Good eye, the carb. is on backwards. Fuel pump right near where the frame arches over the rear axle, close as I could get it to the tank, fuel line runs inside of frame and away from the exhaust. It would be easy enough to bypass the regulator and see what happens. I believe I read somewhere the E type fuel has a lower "boiling" point than the stuff we use to run. Now that I think about it, the easy fix would be not to drive it on days over 100°! Anyway, thanks all for responding.
Put a return style regulator or a return filter on. That's the fix/cure for vapor lock. Vaporived fuel in the line
31Vicky, when you say a "return style regulator" is that a regulator that would normally be used with EFI when there's a line running back to the tank?
Yes, like a heat sink. I would also wrap the copper fuel line with aluminum foil to dissipate the heat.
I know for sure one of the cars that vapor locked in NM was running a return line. When I had EFI on the coupe it never gave any vapor lock problem. Use to add an electric pump the help with vapor lock. Cars in NM were running after market EFI.
Consider that vapor lock problems exist on the inlet, or vacuum side of the pump. Fuel pumps are poorly designed to draw air into the pump inlet. On the pressure side of the pump air is more readily purged from the system. Is the rear mounted electric pump the only fuel pump in the system? Is the tank venting properly? Is the tank, pump or fuel lines routed significantly higher or lower than the carburetor? Any kinks or restriction in the fuel lines? Are the flex hoses still pliable, uncracked and rated for modern fuel blends? How many filters in the system and are they clean? Is the engine in fact starving for fuel or could it be flooding? Have you bought fuel from a different source recently?
Wood does not conduct heat, so cloths pins don't work! If the car runs fine every day other then the one 103* day, not sure I would worry much about it.
I have one electric fuel pump, the mechanical pump has been eliminated. The flex hoses are new, still pliable and rated for E fuel; these lines run inside the frame rails below carb height till reaching the firewall where regulator is located. There are two filters both clean, one at the pump & one just before the carb.. Tank ventilation is whatever Ford had in '36, stock tank and filler neck with vent tube in the neck. I don't have to drive the car on 100° plus days, and I won't now!
But they do insulate. If you put enough of them on the fuel line they will keep it from heating up too fast. The fuel moving through the line doesn't absorb as much heat. So although it seems like it wouldn't work, there is a possibility that it "wood".
The Jalopy Journal
