Its been a long time since my last post. Hope someone can help.

Ok so I know I have seen many posts on here where people are having intermittent/no start problems, but I haven't been able to find my problem.
First off my truck is a 92 F-150 5.0 E4OD 4x4 Dual tanks
Here are the symptoms.
While turning the key the to the run position the fuel pump(s) never turn off. The fuel pump relay does turn off but both pumps continue to run. If I turn on & off the key the pumps will sometimes turn off & the engine will then start. The engine will never start if the fuel pumps do not turn off on their own.
If the engine then starts it may run smoothly for a few minutes but then stumbles & stalls. I noticed that if I get the engine to start & press the O/D button to off & watch the "off" light it will go out (O/D on) when the engine starts to stumble & cannot be turned back off. I have 38 lbs of pressure @ the rail & spark seems to be ok. There are no fuel leaks.
I am guessing that its a EEC problem but I cannot confirm this since it will not throw a code.
Any help is greatly appreciated.

 

It should at least give you #11 or #111 during the KOEO (Key on/ engine off) scan, If their are no active or continuous memory codes.

 

Sorry I should have been more clear. It is giving the 111 code that the eec is working. What I meant by "throwing no codes" is no fault codes. Any Ideas?

 

38 lbs. ob both pumps? What does the pressure read on both when the engine is shut off & how long before the pressure drops off. 1 min.? 2? How much pressure drops? Tried Engine running error code scans? What is your base timing set at. Your sure?

 

Yes 38 lbs on both pumps... strange isn't it. That is the pressure with the engine off. Timing is at factory as I have never moved it since new. I doubt I even could. KOER test has not been possible since it never stays running long enough for that. Haven't tested for pressure drop but will do soon. I did get a reading of 29 lbs with the engine running 2 days ago then it stalled out & went to 38 lbs again.

 

28lbs. running doesn't sound good. Were both pump good previously? 38lbs. not running isn't stellar.

 

Yes both pumps were good. Well as good as I can expect. I replaced both tanks & both pumps about 1 year ago due to leaking tanks. I have never seen more than 30 lbs of presure with the engine running since first checking it over 5 years ago. I still have not had a chance to do a leakdown test, but will try to get it done within the next week.

 

Every time I have run across a no start and the pumps keep running, it has been a faulty PCM. Like you said, if the pumps cut off, it will start. My old man's ranger did the same thing last year, new computer and its all good.

 

Ok so now I just need to make sure that its the computer. Is there any way to test it to see if it is at fault? I just don't wanna spend over $100 if its not... Since its a non refundable item.