Hi, I have the hard start after 1-2.5 hour 00 f150 5.4.

When it won't start up the fuel pressure reads low until cranked. Why wouldn't pressure go up until cranked?

After sitting, key on it can be 10 psi and not go up until cranked and at that point still takes a while to crank?

Is a sensor not picking up the injectors to fire? I don't think fpr is bad by the way.

I've been battling this for a while so any more clues would be great. I cleaned intake, egr works, PVC valve new, don't see any vacuum leaks. New injectors and 6 month old fuel filter. New motorcraft platinum plugs

Thanks!!

 

Also check sensor under under spare tire grey or black box controlled fuel pump known to get corroded to go bad check on YouTube also

 

Watched the video and wow never suspected that. So besides obvious corrosion, any way to test it?

 

gently tap the bottom of the tank when the key is in on position see if you hear a different tone come out of the tank and check the fuel filter if this is your problem hopefully this helps you out

 

Hold up I don't think my truck (2000) has a pump module

 

And with that box on the spare tire is salt or water gets in there it can cause you a whole bunch of trouble they have a remodeled box for that problem I'm not too sure about your year have to check I have seen them on later models also on videos on YouTube I hope I didn't stear you too far off course

 

I've tried tapping the tank to see if the pump would turn back on but it doesn't. I turn key on and I can hear it for 2-3 seconds and then I crank for a second or two and let off and I hear the pump turn on and then this cycle repeats.

I read the 04-ups have a returnless system and mine is a return system so it must not have a module. So I'm trying to figure what would let it leak back to tank? Bad pump check valve?

 

That's a possibility sorry for misse information I'm a YouTube junkie when it comes to Ford trucks

 

Haha me too with youtube. So what do you think about my fuel pressure regulator....it has no fuel in vac line and if vac line is disconnected at idle pressure on the rail goes up. Any possibility it is bad?

I think it's a heat related problem though because it only does it when the engine has gotten hot but hasn't cooled 100% so maybe it's getting fuel/air mix confused

 

that is a possibility but again I'm new to the 1997 and newer style always work on my 1993 Ford f 150 maybe somebody else can charm in could be vapor lock I think is what its called