I have a 1994 f150 5.8. I have been having some hard start issues. I have tried to go through some basic stuff to locate the problem. Both fuel tanks and pumps have been replaced within the last 3 years. The front pump has stopped working completely and I'm fairly certain that the pump is bad. I have been just running off the rear pump which is now starting to give me issues as well. I tested the voltage at the selector switch on the dash and am reading around 7 volts at the switch connector. The switch has continuity where it should. You can hear the rear pump run momentarily as you cycle the key and runs continuously when cranking the engine. Fuel pressure at the rail registers at 10psi. Eventually it will start and once it does the pressure holds steady at 34 psi. I'm hoping someone else has had a similar issue and can shed some light. I'm hoping that it could possibly be the regulator or possibly a wiring/ground issue and not a pump issue. Changing tanks was a pain and living in the rust belt I really don't know how easy it would be to remove the bed to change them. Any ideas guys?

 

It could be a few things of course. 10 psi is why it's hard to start.
A regulator and a fuel filter would be good things to change because even if it doesn't solve the issue new ones are a good idea.
When you first turn the key to on and it primes you want to see about 42 to 45 psi. It should drop about 5 to 8 lbs when you fire it up and it's idling. As you open the throttle, pressure should climb back over 40.
If you end up changing the pumps again maybe go a little higher grade this time.

 

Investigated deeper today and found that it definitely appears to be the pump bleeding back. Cycling the key would barely get me to 10psi but when I grounded the fuel pump pin on the diagnostic port and waited for about 5 seconds the pressure jumped right up to 35psi and stays there as long as the engine is running. Fuel filter was done with the first tank replacement and regulator seems to be doing it's job so now I guess it's time to pull the box and change a pump module. Looking at a Delphi instead of just another Spectra Premium.