My buddy with a 99 psd shut it off and it would not start, checked fuel system and it was good. I suggested a cps but that did not work. A guy drove up claiming to be a ford mechanic said it was the oil pressure switch, said it is very common for theese trucks. He wants to take mine out and stuff it in his truck and Im not real comfortable with that. Can you unplug that SWITCH and jump the two wires togather?

 

Which Oil pressure switch? the Lube oil pressure (Dash Gauge) doesnt matter, The ICP (Injection Control Pressure) Hign Pressure sensor and IPR (Regulator will make a truck not start.

 

If the IPR is at fault, you could just unplug the wiring harness from it as a test. If the PCM cannot read from the IPR, then it defaults to a standard table of values to keep the truck running. If the truck runs (or starts) better with the ICP unplugged, then you have found your problem. Easier than going through the trouble of swapping it out.

 

Its the one on the back side of the hpop. When we were there I checked the hpop and didnt see much oil so I pulled his dipstick and he was not even on the stick, added 3 qaurts to get it on the stick

 

The IPR is what's on the back of the HPOP.

Low oil will definately not help in starting. Did adding oil get his truck running again?

 

The PCM is completely blind to this sensor/switch. Like Alan said, it runs from the sending unit straight to the gauge on the dash. It will not affect the way the truck runs at all, just what you see on the dash.

Edit: The one I'm talking about is on the HPOP resivoir, not down further where the pump is mounted.

 

we removed all sensors one at a time , IPR, oiltemp ect map, cps and swapt em with mine and nothing. Also tested fuel pri and it was good. He pulled the fuel filter put the cap back on and it fired right up, shut it off again and it would not start. What do you think