1995 F150 2wd w/ 5.0 Hard to start and won't stay running. It was hesitating/stalling and i changed the fuel filter. Ran great for a day and now it is hard to get started and if it does, will only run for about 30 seconds. I checked the fuel pressure on the rail and it is only about 20 psi when the system primes and if it starts the pressure drops off and it dies. Could the new filter plug up after a day? The gas that came out of the tank side of the old filter was almost black. what should the pressure be when pump firts runs before it starts. It there a sensor that would shut the engine down after it starts. I got the codes:172, 157,211,542 or 552 and while it was running i got 157 and 998.

 

I guess nobody wants to comment on this one so I will give it a shot.
With the black fuel sludge I would say you need to clean the tanks and maybe replace the fuel pump(s) and filter again (code 172 and 542).
You may also have a bad PIP sensor in the distributor (code 211) and MASS air sensor (code 157).

Or you may have bad wiring and connections in the wiring (code 172, 157, 211, 542, 552 & 998).
Or it could also be a bad computer.

This would be a hard one to tell you what to do without being with the truck.
This is about all I can tell you.

 

Thanks for the reply. i have been searching this site for clues and finally signed up so I could post. I have noticed that you seem to have an extensive knowledge in this area for all of your replies and I am glad that you replied. I haven't replaced either pump yet, I have been trying to eliminate everything else first. I don't have the money to replace something that doesn't need replacing.
It has had some interrmitent hesitation problems for awhile now but it seemed to only be on cool rainy days so I figured that it was needing some routine ignition work. Because once it would warm up it seemed fine.
What/ where is the PIP in the distributor?
I forgot to mention that I did dump some gas in the air intake, after the filter and seemed to start and run OK. Does that seem like it is a fuel delivery problem?
I ran a hot wire from the battery and bypassed the tank selector switch and got the rear tank pump to run and the front tank pump runs sometimes(thanks for one of your previous posts with the diagrahm). I tried to run a hot wire all the way to connector at the front tank but I couldn't get the pump on. I guess I am missing something to do that.
I read some other posts about EEC and the PCM, anything there and what do they do.

It took out about a week and a half ago, and was finally able to have my friend pull me home( thank God for my wife's 1 ton passenger van) and when i unhooked it started right up and I drove it onto the driveway.
Could the filter plug up within a day? I guess I will start there.

Thanks for the reply,
Gary

 

The PIP sensor is mounted on the stator assembly and replaced as one inside the distributor.

Yes it seem like it is a fuel delivery problem. I would work on the fuel problem first and then clear the codes and see what comes back after you get it running.

Sounds like the front pump is bad and setting the 542 code along with the 172 code.

I would work on the PIP (211) and EPC (998) problems until you get the other ones fixed.