[STANG II]

O. K. I have had the 77 for 2 months now and can't solve this problem so I need advice. 1977 Mustang II, 302 V8 2 bbl, automatic, full cuals with no cats, no air.

Engine has had a complete tune up, I rebuilt the distributer and carberator and had the radiator recored to a 4 core with bigger tubes. I am not running a thermostat and the engine seems to be running as it should temperature wise.
The problem is that after about 20 minutes of driving in 100-108 temps the gas literally starts to boil and I loose power. I had a clear gas filter on for a while and it was boiling.
The mechanical fuel pump puts out 8lbs until it heats up and then the presure drops to between 2-3 lbs the carb starts to lean out and then I stall (vapor lock) . If I pour cold water on the pump (which I now carry)the car starts right up and runs for another 10 minutes before it does it again.

Would removing the mechanical and replacing it with an electric located back by the tank cure this problem.
It appears that the heat buildup and poor ventilation under the hood is boiling the gas at the pump, I have tried to insulqte the pump and gas lines but this has only delayed the problem and not cured it.

Any and all suggestions please.

[74stang2togo]

Going to an electric pump could solve the problem, you didn't say whether or not you were using headers, if you are, try wrapping them with a header wrap to keep the excess heat out of the engine compartment. I was also wondering why you are running no thermostat, doing so can make the engine actually run hotter because the coolant is moving too quickly to absorb heat from the engine and transfer it to the radiator, coolant temps would read cooler on a gauge, but the temperatures around the cylinder sleeves and the combustion chambers themselves can actually be hotter. I'd at least run a 160 degree thermostat, regardless of climate, I actually run a 180 stat in my '75 Chevy 1/2 ton with a 3 core radiator, 400cid V8 (notorious for overheating problems in work applications) and an automatic and tow a trailer with it and don't even have my fans hooked up right now. Runs right at 200-210 as long as I don't sit at a stoplight, I ran it without a thermostat last winter because the one she had quit opening and I was completely out of money... she boiled over... with the gauge only reading 180 degrees.

[roadsterII]

you need a thermostat to control your water flow. Pressure makes flow along with the water pump. Cooler engine temp = cooler under hood temp.

[STANG II]

Put in a 180 thermostat as recommended by Ford and still have the same problem, just took a little longer to boil the fuel? I do not have headers just full duals with no cat. Guess I will just have to replace everything till I stumble on the FIX.

[74stang2togo]

Well, if it took longer to boil the fuel, then you might be on the right track, you didn't say what kind of fan you are running, is it a clutch fan by chance? If so, the clutch may be going out on it. Only other things I can think of that would still leave it running hot enough to boil the fuel without the car showing other overheading symptoms is either a head gasket in backwards, or the backing plate behind the water pump being missing. Either could cause it to run hot, while the gauge could still show the temperature in the safe range...