Ford: Truck dies when it gets hot, ford f 150, vacuum lines

Question
QUESTION: 1985 Ford F-150 302 fuel injection.  I have replaced the fuel filter and pump.  It will run great until it gets hot, then it will die and acts like it is starving for fuel.  Once it cools off it will start right up till it gets hot again.

ANSWER: first are you over heating? or is your engine getting REALLY hot?
second, check out your emissions system, after an engine hits operating temp, the EGR (exhaust gas return) valve opens allowing exhaust gas to mix with the air as it is being fed to the engine in the intake (its a heavy 3/4" pipe leading from one of the exhaust pipe back up to the intake) un hook this pipe (on the exhaust side is easiest) and plug both ends, run the truck, if it stays running you have a stuck and bad EGR valve

check over those two things and get back with me and let me know

---------- FOLLOW-UP ----------

QUESTION: The truck is not over heating.  What we are finding out is that air is getting into the fuel line somewhere between the tank and the pump.

Answer
check over your EVAP and emission system, check your fuel cap, a torn or cracked O ring on the gas cap will cause an air leak. look for broken/cracked vacuum lines. a good way to test a line you suspect is to take a can of starting fluid and with the truck running at idle give each line a good shot of starting fluid, if there is a leak it will be sucked up into the motor and for a second the engine will run faster, you will hear a change in the engine's idle speed.

on pre 92 fords pickups they have 2 fuel pumps (for single tank trucks) a high volume low pressure pump in each tank, and a high pressure low volume pump on the frame rail by the driver side door, check that all the connections are on and tight, make sure that both pumps are coming on. I've seen a lot of people drop the tank and put a fuel pump from a 93+ in, as in this year Ford changed from the 2 pump system to a one pump system. this makes it so you only have one to trouble shoot. check your fuel rail pressure at idle, should be around 28-35 PSI, and 10-20 lbs more at 1200 RPM.