97 f-150 fuel delivery problem please help i'm stumped!!!
 

:bows:if you are reading thank you very much for your time!! my 97 f-150 5.4L auto trans has about 180,000 miles but runs and drives like new. i have had it for many years and other than standard maintance it is a great running beautiful truck. untill it recently didn't want to start. and it was because it wasn't getting fuel not an ignition problem. i checked all fuses and relays under the hood for the fuel system and checked the inertia switch behind the pass. side kick pannel, all good , i could hear the fuel pump kick on for a moment like it should to build pressure, but sounded a little rought so i dropped the tank and put in a new fuel pump/screen and put a new in line canister filter in as well. truck started and ran great for about 1 week and then the problem reoccured. i have been reading other posts but they seem to all say what i have already checked. i even tried the jump starting thing i read due to the fact this all started after i put in a new battery although with the current battery the motor will crank over very fast, still no start up. this is however an intermitten problem it doesn't do it all the time, but i have noticed that it seems to onlydo it after the motor has been running and is hot??? but even when it does it if it does finally start it will run perfect untill shut off then maybe it will start back up or not???maybe the fuel pressure regulator??? please help i am stumped?????????:bows::(

Did you clean out the tank when you dropped it?

yes the best i could... it ran fine for about a week and then problem started again but the thing of it is... ieven when it won't start up i can remove the intake off of the throttle body and pour a little gas in it and it will hit and start up and run fine after that???? :help::(

Look for a vacum leak around the fuel psi regulator. You can check your fuel pressure regulator real easy. Go to sears or an auto parts store and get a hand held vacume pump with a guage attached to it. They only cost about $30 or so and are great for all sorts of stuff beside auto repair. My wifes Camaro had the same issue when it was like -5 out side but never did it agin and to this day I never figured what caused the problem. Sorry I couldnt help more. Maybe an Fuel injector?

thank you for the advise i will check that out

If it fires with starting fluid down the throttle body, but doesn' stay running, you have fuel pressure issues. If it stays running, but wont get itself going, then you have a fuel pressure building issue.

what brand pump did you put in it? Dont rule out that you got a faulty pump.
Did you put the filter in the correct direction?

But honestly I'd look at the fuel pressure regulator, especially the vacuum line going into it, or any vacuum line for that matters. Your truck is coming up on 15 years old, on what i imagine are original vacuum lines. I'd replace all of them just for peace of mind.

so if i have a fuel pressure building isse that would relate to the fuel pressure regulator as well correct?

yes basically the regulator controls how much goes into the engine, and how much goes back to the fuel tank, if its stuck open you have too much going back to the tank, and you then loose pressure at the fuel rail.

The pump should always put out more pressure then the engine requires on return style fuel systems

Pick yourself up a Chilton manual a fuel pressure test gauge and an vacuum test gauge, then go to town and test the whole fuel system. With a good repair manual and some inexpensive tools you should be able to figure it out.

Patman03SprCrw I have a question, I just put a pump in my midship tank and when I tested the pressure it was @ 30lbs idling about 37lbs when I hit the gas and 40lbs when i disconnected the vacuum to the regulator. The book call for 30-45 lbs is the minimum acceptable for a new pump, or should it be more so in the 35lb range. Also when I did a static pressure leakage test the pressure increased by 1lb within the minute mark.

Schrader Valve?
 

On the fuel rail their is a black cap. With the ignition tleft off take the cap off
on depress the valve with a small key. Fuel should spray out. The fuel pump has a check valve and the system is always underpressure. If this is the case even if the pressure was low it would cough back fire but it would atleast fire. If you believe your ignition is good and you can verify easy with an extra spark plug and a friend crankin the ignition. You might find it is a bad mass air or cam sensor. I used to have this problem when cars ran map sensors.

Cam sensor fires injectors and mass air flow determines injector pulse width.