06 5.4 screw. This truck sits in the garage all week long as I drive a work van daily. When I take the truck out on the weekends it starts up normally at the house and when I stop someplace for a few minutes it starts right back up but if it sits for an hour or more it will crank over for 10-15 seconds, it does always start back up. It always runs and drives fine, it is all factory as far as the motor, intake, exhaust, tuner etc. Just wondering if anyone else has run into this and what to do with it. Thanks guys

 

forgot to mention, it does crank at normal speed not slowly, just takes a while to fire up

 

No one has any ideas?

 

Bueller........Bueller

 

I've had this happen to my 06 from time to time, but never as frequently as you describe. When I bump the key and it doesn't start, it usually turns over a few times then finally cranks.

 

Bumping this one back to the top as I haven't found any solutions yet. I was thinking fuel filter, but that would be a constant problem, not just when it sits over an hour. I had also thought about the fuel pump check valve but that doesn't explain why it starts normally after sitting in the garage all week. If anyone has any thoughts or suggestions please post up.

 

Too bad I didn't have a question about a leveling kit or tire size, I would have three pages of replies by now.

 

Could be a fuel pressure problem. The fuel rail pressure sensor could be sensing pressure that is not there. When the truck sits for a week, the pressure bleeds off.

When you have the problem, does the fuel pump run when you first turn the key on? If it doesn't that could mean the computer and sensor think there is enough fuel pressure.

The pump in these truck is variable demand. One fuel line from the pump only, no return line. Pressure is controlled by continuously varying the fuel pump speed through the fuel pump driver module (FPDM). All vehicles equipped with ERFS (Electronic Returnless Fuel System) use a fuel rail pressure (FRP) sensor.

 

Thanks for the reply!
Yes I hear the fuel pump run as soon as the key is turned on, whether it starts back up easily or not. This problem is super consistent, always starts after sitting in the garage, always starts right up when only off for a few minutes, always slow to start after getting to operating temp and sitting off for an hour or more.

 

I hate to say it, but you're going to need a diagnostic style code reader to see all of the sensors and PID loops in the computer. You may have a component that is heat or cooldown sensitive. Or it could be something as simple as a loose wire/connector that is sensitive to a heat/cool cycle.

I can give you a list from the service manual of what to check for long crank issues. But the list is long and has mutliple troublehooting subsections.

 

Yes I have a 2005 f150 w/4.6L, and it sits all week, and can be slow to crank at times, I would greatly appeciate any info anyone has.

 

I have 2006 model and had the same problem. It would crank fine in the morning but after sitting for a while, like at work it would have to turn over longer to crank. My issue was the fuel filter. Ten dollars for the filter and a few minutes later and my problem has gone away.

One thing to know about the 2006 F150 fuel filter. There are 3 possible filters for this year (build date 12/05 and earlier, 01/06 and newer, and flex fuel). I thought mine was the flex fuel engine because it will accept E85. Turned out I needed the filter for the 01/06 and newer build. The fuel line for the flex fuel filter was a size smaller.

Chris

 

Thanks, I still haven't changed my fuel filter yet, but will.