Hi all. I have a 2008 F150 4.6. Recently while starting the engine it seems that the cranking time has almost doubled. It doesn't happen all the time. Anybody have any suggestions? Thanks.

 

Have you had your battery and alternator checked? If not, start there.

 

My guess would be the check valve in the fuel pump is not holding fuel pressure while the engine is off so each time you start, the pump is having to rebuild fuel pressure.

Try something. Run the engine, shut it off and then restart after just 2-3 seconds. Does it start normally? Next time, let it sit for about 5 minutes and try to start again. If it takes longer to start after being off for a few minutes, that would indicate the fuel pressure is bleeding off back into the tank resulting in increased cranking time to build fuel pressure. If this is the case, a new fuel pump assembly is needed.

It would be best to double check this with a fuel pressure gauge attached to the service port on the fuel rail.

 

When was the last time the fuel filter was changed ? Plugs ?

 

I have this exact issue with my 04 it just started doing this.
5.4L

 

Start with the cheap stuff: If your fuel filter hasn't been done in the last year, do it now.