I have an 89 f150 4x4 lariat. 302. Some fuel delivery or ignition trouble. It has new injectors, distributor, ignition coil, fuel filter. Truck will crank after several turns and idle well for 10-15 mins. Starts to drop idle and stall when it gets warm. Needs new in-tank fuel delivery unit. (Gauge always reads empty) Not throwing any codes either. Starting point? I read the tfi module can get too hot and cause stalling problem.

 

You need to do 2 things.. put a gauge on the fuel rail to monitor fuel pressure to see if it's dropping when the engine stalls(should be able to borrow one of these from the parts store), and pull codes to see if anything is flagged. You can do that without any special tools but a simple(and cheap) code reader like the Equus 3145 is a good investment.

 

Fuel pressure OK. Put in new in-tank sending unit w/ low pressure pump. Truck will idle perfectly. Now it will run fine but after getting warm it will seem to struggle to pull its own weight. Eventually will cut off. When it cools, whole cycle starts over.