1999 7.3. First starting the truck it runs and idles great. But only after a few minutes of driving it’s starts to lose power and bog down. It will go away after a few seconds of increasing the RPMs but then idles rough and happens again. Hasn’t died yet. Buddy says it might be a bad CPS. Also I’m noticing when this happens my RPMs will get stuck around 11-1200 RPMs and then drop way down to about 500 The truck always idled at about 750 800. Any ideas?

 

Sounds like a possible fuel delivery problem. Theoretically the fuel bowl will be full by the time you try to start but if the pump is weak or there are issues with the in-tank screens it will eventually starve out. The main lump in the gravy here is it will clear up when you rev up the engine. Is this under load or sitting?

 

Your tank 1/4 or less? Also, look down in the valley, behind the fuel bowl. Off center, to the right, there's a sensor, IPR. It has a funny looking nut on the end of it. Make sure that ain't loose/missing

 

 

 

Just a wild shot in the dark, but have you checked the EBPV for proper operation? Linkage connected, ETC?

 

Check the ICP for oil in the electrical plug (sensor in middle of drivers side head) When mine went bad it had similar symptoms

 

Doe it have a CEL or you have a tuner see of you got any trouble codes. Sounds like the IPR is going away but it will usually just die, cool off then run for a minute and die. If it was a CPS it would'nt start at all. What is your ICP pressure at idle. 7.3 has to have 500 psi or so to run at idle. Is your Turbo dirty check for free wheeling and make sure it's not chewed up. What's your fuel pressure? could be a ****load of things.

 

a truck that old check your two filter inside your fuel tank and look into the hutch mod if you havent

 

I’m going to start ripping into in tonight after work thanks for the info guys I’ll keep you updated