1991 f250 Fuel injected 351W E40D 4x4

Over the summer it took longer and longer for the fuel pump to shutoff.
As long as the fuel pump is running the truck won't start. If it does happen
to start it runs rough, check engine light is on, truck will not move forward,
overdrive switch does not work until after a while motor smooths out , fuel pump cuts off and everything is fine. Truck rarely starts now.
I can't find what tells the computer that fuel pressure has been reached and switches the relays and fuel pump off.
I have spark, 45 lbs fuel pressure, new FP and EEC relay, new EVP sensor and EEC water temp sensor checks ok and so does fuel regulator. I previously had a EGR code and MLPS code but now only have a running code of 632, Overdrive switch not changing states.

There are multiple posings of this exact same problem on the web without a posted solution.

Did anyone find a solution? Does anyone have any ideas?

Thanks,

 

any one ? i have the same prob.. canf figure it out yet.. but mine is a bit different once it starts it runs ok ..

 

Replace the computer.
The fuel pumps are timed, they do not shut off by pressure.

 

classic symptom of a bad computer.

 

Thanks everyone. Finally got the nerve and bought a computer. It started right up without hesitation. It's been a week now, started every day.

 

glad you got her fixed and thanks for the update.

 

i guess its time to get a new computer to.. where did you get one and for howmuch?

 

I bought a remanufactured one at the local mom and pop auto parts for $135 plus tax. Everyone seems to have them, Autozone,etc.

 

Same problem, happy I found this post before replacing more parts.
Tested pressure on lines and fuel rail, changed pressure regulator (darn the intake placement), replaced both relays (the EEC relay had a burnt and corroded terminal which made me hopeful). I have spark and pressure on all lines. I almost took it to someone (which would be a first), but now I'll swap the computer. THANKS!

 

yeah i swapped computer and my truck is fine now..

 

glad you guys are getting it fixed with the computer replacement.