89 f150 stalls, restarts after sitting

[greasemonkeyjmj]

i have a 89 f150 4x4 with 5.0 engine and 93k original miles while driving, it will start to surge and die going down the road.the length of time it runs varies depending on the outside temp.you can let it set for about 10 minutes and start it up and go again.usually if you start it too soon it will run extremely rough and labor knock and usually die again.i have changed the low pressure pump in the tank, the high pressure frame mounted pump, the fuel relay,and fuel filter,the tank looked good and clean inside. i have also changed the ignition module, and the idle vacuum motor, the idle vacuum was because of the normal ford dying on startup problems,i have no CEL coming on with this problem. i dont have a fuel pressure guage, last time it died, i pushed in the schraeder valve on the fuel rail, it seemed to have lots of pressure on it, but there wasnt much gas at all coming out, mostly just air. please reply if you have any idea what to check. i cant afford to spend big dollars to have a lot of diag test or trouble shooting done. as it stands right now, if i cant find out what it is, i am looking at having to sell the truck and buy something else.. also i dont think it is a fire problem, because one time it did it, i checked the fire and it seemed to be a good spark .

thanks