hello,i'm new here and i hope someone can help,cuz i'm not a mechanic.i have a e250 4.9 L that won't start.i've replaced the fuel pumps,filter,tsp,plugs,wires,cap and rotor.i have spark,and fuel is present at the rail,but she won't start.i checked enertia sw.,fuses,pump volume,and all seems well.i did not replace o2 sensor i'm stumped.o.k., now i've removed the fuel rail and cleaned the injectors and guess what? nope still won't go. it cranks and starts for a few seconds here and there and if i feather the pedal,it will run for a few more moments and then stall.i ran the tank dry(my own stupid fault,but i was in the middle of nowhere and no gas stations)and before i did anything it would run but just barely,now it won't stay running enough to even move it.o.k. now i'm gonna replace the eec relay and hope the comp. ain't cooked.o.k. relays are working fuel delivery is weak aft of forward pump gonna check new filter again.i also replaced the ign. module at distributor.if this thing ever starts i'll have a real good runnin van,considering the horrible condition of all that i replaced,it looks like this poor van was NEVER serviced before.anyone got any ideas,cuz i'm runnin out of stuff to change?well i'm getting good fuel now,replaced the new filter again,and she just won't stay running.gonna try a map sensor next,this comp. is not stocked anywhere in this town so map is cheaper and handy,so.........here goes.well it must be the computer,and now i gotta wait cuz noone has this comp. locally .f0tf-12a650-ja new comp. ordered and all i can do now is wait,but i gotta say that starting at the cheapest thing first don't always work out,but it's a sure-fire way to get a lot of routine maint. done in a hurry,especially when the vehicle is your bread and butter! i love me a ford ,but this van is really loaded with electronics GEEZ! longin for the days of tweaking a good ole carb. like i had on my 71 3/4 ton .plugged-in comp. and no good,same thing.H E L P! now i've replaced the egr position sensor,and..............you guessed it,no good.well, i'm done with it,she's goin to the shop.I also might add that this forum has been absolutely useless to me,so good luck to anyone lookin for answers here,cuz i got none.goodbye,and god's speed.

DUDE IM HAVING THE SAME PROBLEM RIGHT NOW AND WAS WONDERING IF YOU CAME TO A COMCLUSION . I HAVE REPLACED ALL THE SAME STUFF YOU LISTED I HAVE A 90 ECONOLINE 4.9 AS WELL. WHEN I SPARAY STARTING FLUID INSIDE OF THE AIR INTAKE IT STARTS BUT SPUTERS WHEN YOU TRY TO DRIVE IT. PLEASE GET BACK TO ME MI MECHANIC NOW IS TELLING ME THE INJECTORS BUT I C U TRIED THAT AND NOTHING SO PLEASE GET BACK TO ME . MY AIM IS LIVEPHC IF YOU HAVE AOL THANKS FOR YOUR TIME

Have you checked the fule pressure in the fuel rail? I had the same problem with my 1989 E150 5.0L. Changed the fuel pressure regulator in mine and it started and ran great.

Try the timing chain. Pull off the distributor cap and turn over and watch if the rotor is spinning. If not the timing chain could be snapped. If you have a clutch fan - keep in mind that some have reverse threaded main shaft. I would love a chart for that - which are reversed and which aren't.