1995 F150, 300/6 stick. one fuel tank

Starting roughly 3 months ago my afformentioned F150 quits. A senario; driving doen the freeway that ole familiar feeling in the throttle, no power. The truck is still runnung and starts missing and sounds like its starving for fuel as it start hunting trying to stay running. Evntually, withing 5 seconds gives up and quits. Will not start immediately. If ya let her sit for about 10 minutes she will fire and run for around 30 seconds then starts missing, hunting and quits. This same behavior will continue unless you let it col down completely, no symptoms for a month or so after that. Then radomly does it again in any kinda driving condition. The longer or shorter you let it sit after one of its episodes the longer or shorter it will run there after. To the ear it sounds like its starving for fuel. There is nothing you can do to keep it running like the ole carburators. I did notice if you get it to buzz around 3,500 rpm's while its doing this it won't let it quit or miss, anything really just keeps buzzing. If ya let it drop rpm's it won't let itself pick itelf back up, just misses, kicks and fades out. It never just quits like an electrical problem or stator/pip. Fuel pump sounds good and the filter has been changed 3 times. All four times this has happend I have pulled the exit side line off the fuel filter and gotta bunch of air otta there. I though vapor lock then maybe the tank has pressure in it, nope on the tank. No hissing when I remove the cap. Once I re-attach the line to the filter it still won't fire, just stummbles over itself and hits a few but wont fire. Letting it sit gets more run time. letting it cool makes it go away for a month or so. I've read as much as I could on here and everone seems to have issues with the PIP, but mine doesnt just quit immediately and doest have hard starts, never has? I understand that I live in Nevada and its HOT! Things get heat soaked but today was only 103 'F and its driven in 120'f with no problems. My guess its the PIP somehow. It only has issues once every month or so, one time then goes away after cooling??

Thanks for any input, I know this problem sounds familliar to others that have posted but theirs are more consistant and reaccurring.

 

At first I thought that it was just something getting hot, but I wonder if you could have a small leak in the fuel line that only opens up when it gets hot.

Something like that

That would kind of explain why it will run at higher rpms -- it's sucking in enough fuel to keep going.

Or maybe there's something that gets sucked into the fuel line in back of the filter and blocks it up. Could settle back when the truck cools down.

These are just guesses, but it sure does sound like a fuel issue -- especially if it has air in the line when it quits.

Have you ever checked to see if the fuel pump spits gas right after it quits ?
Maybe the pump fails at high temps.

Good luck

 

Thanks for the help! That pump can get hot and drop below the pressure specs... Hmm.. I though about dumping some cold fuel in the tank once it started doing this, it doesnt run long enough to get there though lol! I aways thought pumps just quit when they took a dump? Not always I guess. It primes nice and sound strong, but if it drops below 38 lbs it could start missing and starving itself for fuel. It fires RIGHT up after 10 mins and runs for 30 seconds. Last night after it cooled all the way down it fired and sat there for 15 mins., running like a 300/6 does. No problem or signs as if nothing ever happened. Sooo, whatever it is its getting hot and tired and shutting down and not holding up to its end of the deal.. The way is sounds its most likely a fuel pressure problem,,,,, only sometimes lOl!!
Thanks again!!

 

My guess would be that the coil is giving up, it happens that when it gets old and is ready for a replacement, it starts to be pretty sensitive to high temperatures.

 

They start missing like that?
Certainly a good possibilty.
Thank you