Maybe I'm going crazy but this has happened twice in the past 6 months and I cannot, for the life of me, figure out what is wrong. Here's the spec's: 2000, F-150 XLT, 4.6L w/ 80k mi. The problem is that occasionally when I go to start it up it will crank and turn over but won't fire up. Kind of like it's starving for fuel. The first time this happend I let it set for and hour or two and she fired right up without any hestitation. The second time took a few more hours of sitting before it would do anything. This usually happens after I make a quick stop and shut it down and then try to start it a couple of minutes later. Checked the fuel filter, pump, etc. Anyone have this happen to them before?

 

Checked fuel filter? Did you replace it?

 

Yeah, I did replace the fuel filter. I actually had it towed to the shop last night but when the tech tried to start it up this morning she fired right up. They found that the computer was spitting out no error codes and that everything was fine. They must think that I'm some kind of hypochondriac or something.

 

Have you installed any mods? Done any work to the truck? Have a look at the crank sensor to be sure it is plugged in properly.

Regards

Jean Marc Chartier

 

I glad I am not the only one. My 1999 F150 XLT w/4.6L has being doing the same starting at about 75K. The first time in Jan 2004; I changed the Fuel Filter. The next two times I just waited until the next day and it ran like new. The symptom; it cranks but will not start; wait the next day at it runs great.

This happens now about once per month (4 times now). I thought it was a gas line freezing issue, but it happend at amient of 60 F the last time. Could it be a 10% ethanol fuel related, or fuel spec.? Could it be contol chip related? Truck is now unreliable. Any suggestion would be wonderful. Thanks

 

same problem i have a 01 xlt 34,000 on it out of warrenty, but i do have mods, but it has done it before i ever did any mods to it, same thing if i drive it say under 5 miles stop and in lless than twn mins later get back in it and try to start it doesnt, i let it sit for a min, and it starts right up, no codes are showing nothing, I think it is could be my two cents, that it is maybe some sort of condensation in the intake or on a sensor, that the engine hasnt got hot enough to dissapate the condensation, id love ot find out ,, OH it happens a lot when it is humid out any tempature but mostly when it is humd

 

I had a similar problem on a Maxima and it was related to the fuel pump. It seemed that the pump worked ok part of the time when I started it. Do the F150's give out codes when the fuel pump fails?

You also might consider vapor lock...

http://autorepair.about.com/library/faqs/bl828.htm

Or your fuel system is not retaining pressure when you shut the engine off...

http://home1.gte.net/web10dn5/euask1.htm

 

Thanks for the feed back. I will scan for codes.

 

Do any of you have Exhaust muffer modifications to your vehicles or missing cat shields. You could try the higher octane fuel to see if it makes a difference. Im not sure if the fuel with alcohol in it is more likely to contribute to vapor lock or not. You might be able to verify the vapor lock thing by spraying the ENTIRE fuel line with water to cool it off and then try to start the engine.

Here is a thread where a person evacuated vapor from the schraeder valve on the fuel rail but I do not think spraying gasoline on a hot engine is cool as it could cause a fire or explode. It would be better to have a hose to evacuate it into a container outside the engine compartment.

http://66.179.14.118/forums/showthre...ght=vapor+lock

 

i have a magnaflow ex on it and a superchips tuner and K&N intake, i also use 91-93 octane its so intermitent, like once every 4 months or so id like to knwo if anyone who has added a high performance MAF sensor has had this problem, i also have a friend that has a 98 f-150 his does the same he has no mods what so ever his also hesistates sometimes on humid days when he is pulling away from say a toll booth on the highway, driving for 40 or so miles then coming to a stop pulling away, his hesitates then around 40 mph another weird problem

 

I dont know it sounds like a fuel thing to me. Next time it happens remove your gas cap to see if it is creating a vacum. It happend on a bus that i worked on. New gas cap and she was as good as new.

 

I checked the codes - no faults. Fuel pressure - 35 psi. Tried the gas cap thing, no change. Tried the schrader valve thing no change. Battery fine. I suspect possibly clogged or sticky injectors?.. I added injector cleaner.

 

check crank shaft sensor and cam shaft sensor

 

Thanks - will give that a test

 

dad's been a mechanic for 19 years for Ford and i couldnt figure out what ur problem was and i mention to him what ur problem was and he immediatly told me to say check that. he said that is where your problem is.