1996 f250 with a 351. Not a daily driver so she had been neglected but went out the other day to start and she was a no go. I dont have a fuel pressure tester but here is what i do have figured out. My rear fuel pump is working and my front pump with 205 miles on it died so i rolled the key forward heard the rear pump run flipped it to the front tank and cranked to motor for a few seconds. when i hit the valve on the fuel rail still had, what seems to me, to much pressure. I do not know if the failure in the fuel pump and this issue are related but it seems possible. also when i crank it on the rear tank it sounds like it is trying to hit on one cylinder, but that could just be me. any ideas/suggestions?

 

Buy a fuel pressure gauge.
Check for spark.
Check for injector clicking.
Check a spark plug to see if it is wet.
Does the selected fuel pump run for one second and quit when you turn on the key and not try to start it?

 

thanks for the reply and sorry for the delay. New problems discovered that I think are contributing factors. Long story short I replace mid-ship fuel pump a year ago, pump went bad and truck stopped running around the same time, broke filler neck when replacing pump, was sold "fuel line" to replace filler neck that turned out to be coolant line that turned into goo. Now crap in tank and whatever that combination created ate my float and strainer. Tried fuel pressure gauge but it filled up with gas so going to get a new one. Question. since I have my mid-ship tank and pump down can I bybass that part of the system to continue my testing on my fuel system or for that matter fix and drive it like that until i get money for parts?

 

No you need to put the mid tank back up with its fuel pump with its fuel lines hooked up.
Then you can test and run off the rear tank.
The each pump in the front and rear tank has valves to block both the supply and return fuel lines.
So yes you can test and run it without spending any more money. Just keep the rear tank selected.

 

ok cranking the engine over I got it up to 30psi once after cranking for about 25-30 seconds. Pressure builds slow and holds. I averaged about 23 psi over the course of 3 seperate tests. Guage would drop 2-3 psi in the first 2 minutes but then would hold.

 

You to get the fuel pressure above 30psi to start the engine.
Ground pin #6 of the self-test plug and turn on the key. You should get around 45psi pressure.

 

got 32 psi after about 8 second run. cranked it over and to run. Sounds like it is hitting on one cylinder every now and then.