Exp wont start. turns over but wont catch.

[dchilds]

ive been having some problems with my 2000 expedition. it just wont start. i had it towed to firestone and they said that they were getting the indication that there was no fuel pressure. apon replacing the fuel pump and assembly, they were still getting the same indication and it wouldnt start so they put the old fuel pump back in. the next morning the truck started right up and they have no idea as to why it is doing this. it lasted about 3 weeks and it happened again and i had it towed again but when it arrived to firestone, it started right up. its been fine for about a month and it has stopped again. i have an after market alarm and remote start and they say it may have something to do with that. if anyone has any idea as to why this is happening, please let me know. thank you

 

[panda24619]

thats weird. it could be something with the alarm. is there an alarm box somewhere with a reset button you can press? my gfs car has a problem with her alarm box. she just presses the button and it starts right up. also change the fuel filter. it could be clogged up.

 

[WHOISMOOTOO]

Im about 95% positive its the fuel pump there funny like that, just have it replaced! I had the same issue about a year ago where my truck wouldnt start or hard to start then when i had it towed to the shop it would start right up, finally i just had it replaced and no problems since, also make sure you are changing out your fuel filter regularly around every 15k

 

[Racenut]

More than likley it is in the PATS sercurity system. When the pats system is activated it cuts power to the fuel injectors to cause a no start condition. It could be in your alarm or it could be that your factory key is going bad.

 

[tmajikman]

Do these trucks have a fuel pressure regulator, if so it could be going bad, or the prime could be bleeding off. Try to spray starting fluid in the intake next time it happens and see if it fires right up for a few seconds.

 

[secondechomatt]

when it won't start, does the tach bump at all?

try starting it with your foot to the floor on the gas pedal.

then try starting it with your foot off, then gradually easing into it.

finally, unplug the maf and try starting it. If that works, as silly as it sounds, the cold start wire on the maf is dirty. Pull it, clean it and should be fine.

 

[Lane24]

Mine did the same after I got my remote starter. It would start fine alomost all the time, and then when it got cold, it would try to start, and then not catch, and would keep doing it over and over until I ran out and touched the brake, and started it manually. Something wasn't connecting in the PATS bypass when it got to cold. Not to mention, I had the wrong bypass to start with. They had put in a bypasss that required the key inside. They were trying to get a PATS2 one to work, when mine was actually a PATS1 due to it being produced early in the model year. Once they found the proper bypass, and reinstalled it, it worked fine.
Your key transponder might even actually be going bad.