2006 FX4 has developed hard start issues lately. I'm thinking it may be related to the heat. It's been extremely hot here and when the heat wave started that's when the truck started having issues. I do shut the air off before I turn the truck off so I'm not starting it with the air on. Yesterday after work the dash temp said 117. I cranked it for about 5 seconds, turned the key back off and cranked it again and it started. But it's almost like the auto choke isn't coming on all the time. Make sense? It doesn't idle high and then kick down.

Thanks

 

mine hates hot weather... my will act up when i give it gas on really hot 100+ days... like it bogs... chocking for air..... i keep my air filter a little cleaner during the hot mths too.. if the filter is clogged i get back shaking on shifts and accel... once i clean it...it all goes away!

good luck

 

there could be a number of things that would cause your problem a failing fuel pump or pressure regulator or a fuel pump relay sticking. when it does it again pull the line off the regulator a see if have fuel.

 

If you haven't done it for awhile or never, change your fuel filter.

 

x-2 on filter

 

I don't belive it's the weather, I'm visting my parents in Baja CA and it gets up to 110 of pure hot heat and inside my 06 it says 120 and my truck always starts with the first try. I think you might want to look in to this problem, maybe you need to get it serviced our some thing.

 

I just filled up with fuel today. I don't think I've filled up since it started acting up. When I went to take my fuel cap off I noticed it wasn't tight. The last time I filled up I must not have tightened it until it clicked. Also that fillup was with 10j% ethanol in Missouri. It is a flex fuel truck so that shouldn't matter. Would the cap being loose cause this? Possibly not holding fuel line pressure? Just a thought.

Fuel filter was just done 15k ago so it is due I guess. It's strange the truck runs great otherwise. No weird dying issues, surging or anything. I have GOT to find out what is going on though. It's doing it constantly now. It starts normal about 1 out of 4 tries. Pretty embarrassing. I've only started it 3 times since getting fuel today and it did it 2 out of the 3.

 

Where's the pressure regulator located? Mine's a flex fuel if that matters. I did a search but I don't see any posts regarding the regulator and 04+ trucks.

 

Fuel cap will have nothing to do with starting issues

This sounds like a fuel pump. Someone did mention a relay. That very could be it as well. You may want to bring by a shop. Without some mechanical expertise you probably won't be able to guess your way through it.

 

nevermind

 

My reply wasn't showing up....

I'm mechanically inclined. That's not a problem.

I'm wondering if I don't have an injector sticking open. I wish jet would reply back and tell me where the pressure regulator and/or the fuel pump relay is. Is the fuel pump relay the one mounted on the frame above the spare tire?

I guess if neither of those two are the issue I'll pull the fuel rail and check for a leaky injector.

 

There's another thread here somewhere on the fuel pump relay on the 04+ - it's not obvious where it is and it's not in the manual. It's on a hidden circuit board somewhere as I remember.

 

mxracer49 glad you found the other thread and found the location i would have never guessed the location of the relay hope you have the problem fixed

 

Found it, thanks glc. I'll be checking it and the fuel pump driver module tonight.

I'm wondering if the FPDM is what Jet is calling the regulator.

 

Update so far on this. A couple members are helping me out in another thread on Actual Fuel Rail Pressure readings from their programmers.

Trying to figure out if I have leaking injector(s). Mine drops down to 25psi. So the system not holding pressure that's for sure. I think key on not running the fuel pressure is suppose to be 35 to 48. Mine isn't.

So now I need to figure out if the injectors is the only place it can lose that pressure. BUT, I haven't put a filter on for 15k or so. I'm going to put a filter on tomorrow and see if it helps it at all. I don't think the filter is the cause because my pressure is 38-39psi with the truck running. I wouldn't think a fuel filter that has 20k on it (just looked at my maint records it has been 20k) would restrict fuel pressure by that much but I hope I'm wrong.

If it is a leaky injector I'm going to see if it's covered under the extended warranty since the truck was actually built 12/05 even though it's an 06. Just thought I'd update for future searches/reference.