mithesaint

2001 F150 5.4 Supercrew Lariat. 145K miles.

I've had the truck a little over a year. It's primarily a winter beater and haul stuff type of truck. I have a Buick Regal as my daily driver. Lately, the weather's been pretty cold and nasty here, and I've been having trouble getting the beast started. As long as it's above 20 degrees, it starts ok. But, once the temp drops below 20 and the truck sits for more than a few hours, it takes multiple attempts to start. It cranks over ok, but doesn't want to keep running. It seemingly runs fine once it gets going.

Borrowed the test kit from Autozone, hooked it up to the Schrader valve on the fuel rail, and got 0. Nothing, even while the engine was running. I'm 99% sure I had it hooked up right. Seemed pretty straightforward to me. Disconnected the kit, and simply pressed down on the valve, and got a tiny bit of gas out, but not the spray I was expecting. Did that within a few minutes of running the truck.

I'm thinking this is probably the fuel pump right? The fuel filter looks sorta new, not rusty like the rest of the truck! I guess it could be the check valve, but I would think it would always have problems starting, regardless of temperature.

Am I on the right track? How difficult would this replacement be for a below average mechanic with average tools and limited spare time in an unheated garage? Any brand of pump to use or avoid? Thanks.

BareBonesXL

If pretty cold means really really cold you might have water in your fuel, freezing. Just a guess. But, you're jumping way ahead to fuel pump when you haven't checked the easy stuff like fuel filter. Disconnect the inlet and see if you have good flow. Compare to the outlet if inlet looks good. Stuff like that.

Fordrocks689

Does the fuel pump turn on when you cycle the key?

mithesaint

Yes. I can hear the pump run.

Jbrew

Yea, a pressure check doesn't lie. Could be the pump is wearing, this cold weather will help that along. Could of cracked the tube on the pump itself. Worst thing in this weather is running down below half tank. THAT shouldn't matter but it might. We are setting records in MI for cold weather, it picks on everything.

However, swap the filter out and test again. Listen to the pump the best you can. It might hint towards a health problem. Normally, in all weather, when the pump begins to go, they start to lock up or freeze. It's for this reason banging on the tank can get you home vs stranded.

mithesaint

Wanted to add some follow up to this post, since it seems that most "I have a problem" posts seem to end without any resolution.

I was having trouble believing that the pressure of 0 was correct, given that the truck was running normally otherwise, so I looked elsewhere. I found another post where someone was having similar issues, and it turned out to be the IAC valve.

The part was only $42, and I had a $20 reward at Autozone that I needed to use or I would lose it, so I bought a new IAC valve. 15 minutes later, the truck starts normally again. I also cleaned the throttle body and MAF at the same time, but I'm pretty sure it was the IAC valve. The truck fired up right away this morning after sitting outside overnight in 5 degree temps, so I think I'm good to go.

Thanks to all for the advice.

Jbrew

Glad you got it fixed and thanks for letting us know you didn't simply check pressure gauge function. Had the wrong adapter I expect.