On Saturday, woke up early to go play some golf with some friends. Weather was in the upper 20's in the AM, and rose to upper 30's in the mid-late afternoon. Truck cranked up perfectly in the morning heading to the golf course. Played our round, and came back to my truck to load up and leave, tried to crank it, and it was just cranking over but not firing. Tried all I could think of, tried turning it to the run position to let the pump prime the engine, that didn't work. Tried letting it sit for a min and wacked the fuel pump/tank with a 9iron hoping to fix the problem, nothing. I was stumped and very pissed about this. My buddies and I were waiting around for a ride to come pick us up, and one of my friends says "give it one last shot".
I did just that and she fired right up...
I drove back home and Sunday morning came around and went to start her again, worked perfectly. Later that evening, went out to crank it again, and it did not work the first time. I proceeded to turn the key off, sit for a second, and the turn the key to run to prime the engine for about 3 seconds, cranked it and it fired right up.

My question is: could this be the fuel pump its self going bad in this colder weather?
Could I have a bad connection somewhere or could the colder weather just need more time to prime my engine? Im confused and am seeking guidance.

Truck is a 2001 F150 SCrew KR 4x4 5.4L V-8 with 135,xxx.

Thanks!!

 

Sounds like a the pump to me. You've done the common tests (prime it and whack it).

You could test for fuel pressure on the fuel rails to be sure. Should be around 35psi when primed.

 

How do I go about checking the fuel pressure? And if it's below ~35psi on the first attempt, that would be a positive sign that the pump is going out?

 

My truck did the same thing a couple weeks back. Fuel pump.


I replaced it with a Bosch from advance auto for about $90. Just got the pump and used the old assembly. You can save time by getting a pump and assembly, but the cheapest I found was like $160 and the pump was not as good. Motorcrafts are around $350 for the whole assembly.

 

That happened periodically with my 03 and I'm in socal where there is no weather. Suspected my fuel pump was going, but totaled it soon thereafter. Cold weather might be exacerbating your problem, but I don't think it's causing it.

Until you do go about replacing it, the only thing that helped turn mine over was having it not turn over several times, then turning the key off and letting it sit for a minute before trying again. Usually started right up after.

Lucky it was in your driveway. First time it happened to me I was four hours out from mine.

 

Time to slide the box back

 

You should be able to hear the fuel pump go on for a short burst when you turn on the key. Have a buddy turn on the key while you listen at the fuel filler.

If you hear it going on, you might try changing the fuel filter. real low cost

Also, check to make sure you are getting spark. the PCM takes reading from the cam shaft sensor and crank sensor and then sends spark. When it does not get a reading, it doesn't send spark. One of your sensors could be dirty and not giving a consistent reading.

You should be able to get a fuel pressure gage from autozone for free. Test the pressure at the fuel rail.

 

Sound similar to an issue I had. The problem would only act up in cold weather. Never had an issue in the spring or summer. Switch out fuel pump and haven't had an issue starting since.