fx4gxp

I've got a 2011 FX4 Ecoboost with 4,500 miles on it. Over the past 1,000 miles I randomly get an extended crank when first starting the engine in the morning or leaving work. It just sits and cranks over 3 or 4 full seconds then finally starts. I had it into the dealer, but it wasn't acting up then. Anyone else experience this? or know what it is?

brass0

Mine has done this a few times (2700 miles now). It doesn't occur so much on cold starts in the morning, but rather after I drive short distances, such as to work and park it for a few hours. If I go out for lunch and return, the truck will take longer to crank when I am ready to go home for the evening. I thought I had read a thread here regarding this. If I recall correctly, it wasn't anything to worry about YET.

LS1POWERED

Mine also does this on occasion. I have noticed I can make it do it by just inserting the key letting it sit for 10-15 seconds then turning it to start. (noticed this waiting on the wife to buckle in the little guy)

Tuner Boost

Try this and repost back on the results. Turn key to on, but dont crank. Turn off, then turn on again then crank. If it is what I suspect it will fire right up.

93Cobra#2771

iTrader: (2)

You thinking fuel pressure is bleeding off a bit?

Tothemax

What temps?

When it was -20 mine cranked over for 4ish seconds before starting.

jwanck11

Tracy, do tell! This happens to mine infrequently along with an expected slower crank on really cold (single digit or colder) mornings.

Tuner Boost

Bingo. Yes, either backflowing or an injector leaking down, so the key-prime will determine if thats it.

Nice to see more intelligent techs here!

Tothemax

Interesting. I'll have to remember to try this next time it's cold out. Doubt we will get below 0 but you never know.

93Cobra#2771

iTrader: (2)

Thanks for the compliment. 100% backyard wrencher, and self taught tuner with old school TwEECer software on my 93 Cobra.

On the old style return type fuel system, I'd blame a faulty fuel pressure regulator for the same symptoms...