I am helping a buddy diagnose a problem he is having with his 99 (11/98 build date) f250 that has 160,000 miles, auto, 4x4, SCLB, XLT.

Several times he has had the engine shut down completely when he was going 60mph down the freeway. Gauges still work, doesn't loose electrical power, just stops running while he coasts at 60mph. After holding his breath for three seconds, the engine will fire back up and he continues driving as normal. It will actually restart on its own with out even touching the ignition key and still in drive. Kind of like popping the clutch while it is rolling, but it is an auto.

My first thought was CPS. He took it to the dealer last week after I told him of the recall, but the problem continues with the new CPS. Any thoughts??

 

Has he ever replaced the fuel pump on the frame rail? If not, it might be the problem. It might be going out. My son-in-law's 99, built date 8-98, fuel pump went bad at about 150K.. kinda acted the same.. it would run and it wouldn't.. Next time it dies, without trying to restart it, remove the fuel filter cap and check to see if fuel is near the top..

 

UVC wires loose ?? Maybe....

 

Check the main engine wiring harness for chaffing. The harness runs up and over the driver side valve cover. Look for chaffing at the valve cover, and above the valve cover where the harness runs through a bracket. Did the water in fuel light and SES light flash when the engine stalled? Mine did.

 

No SES. No lights flashing. All dash lights illuminate as though he shut down the engine and is restarting it; Oil, WTS, ABS Seat belt, low fuel, ect (there are more but I can't think of them all). It is the normal system check that the truck goes through when you fire it up.

 

bad EEC relay maybe.. Guessing.