[G.M.]

You had me baffled for a few minutes. The 38C is 100F. I wondered how things got hot at 38F. Raiseing the fuel pump should lower the temperature of the fuel in the pump some but heat also rises so the engine heat is all going up under the top of the hood so it may not help. I don't know what kind of gas you have in Argentina but we have ethenal and other blends of fuel that are causeing problems in the pumps in hot temperatures here. Just to try to pin the spot where the problem is I would put a plastic bag of ice on top of the pump and see if it helps. The other problem with the same effect is a hot coil or condensor. Again a bag of ice on the coil and condensor will cool it in about 10 minutes. A coil or condensor will usually cool in about a half an hour. This is about the same time it takes to change the fuel pump. The pump is changed, the coil cooled and the engine starts. This fooled millions of people for years. Skip Haney an old Ford coil rebuilder has rebuilt 1,000s of coils and "fixed" the vapor lock problem in the pump. But for the past few years real vapor lock is back forming in the pump from this new fuel. I had it on a 1,000 mile trip at 100F or 38C 10 or 12 times. I finially found that if I was moveing above 55 miles per hour I didn't get it and below it started. At 55 there was enough fuel being used that fuel was cool enough that it didn't lock. Below 55 the fuel was in the pump longer and got to hot. I was thinking of a small adjustable return line to the tank to keep the flow higher to coll the pump. The carb has a metering hole at the needle valve of about .100 and the hole in the fuel line is much larger so a small return line with a .060 hole would still allow enough fuel to the carb. I have been involved in a few large projects for the past year and haven't had time to try the return. On my 1,000 mile return trip the temperatures were below 90 and I didn't have the problem. G.M.