For a while now my '99 F-150 5.4L SuperCab has been having like a miss when accelerating. Most noticable between 1000-2000 RPMs it will feel as though the engine stumbles. Hard to pick up RPMs when it does this, This morning on the way to work it done something new though, it started the normal every morning stumble but when I left a stop sign, made a turn and push back down on the gas the engine just QUIT just like someone turned off the key. After coasting to the side of the road I tried to restart but it just whirled over and over and never hit a lick. After sitting about 5 min. I hit the starter and it whirled for a few time then started, I went on to work but it stumbled all the way, I could even notice it slightly at highter RPM today (Around 2500).
It's done all this with NO lights, I've had to the dealer two times to have them check it out both times they said the computer didn't show anything and they couldn't find anything wrong. Both time they gladly charged me $52 for computer hookup.
It doesn't have the miss all the time??? I'm really getting frustrated with it now.
Anyone have any ideas what to try next.
I've already changed tranny fluid, and cleaned the TB real good, and changed the fuel filter.
If you need any additonal Info. just let me know, I really need to get this figured out.


Thanks, JDBob

1999 F-150 5.4 Oxford White Off-Road
K&N air filter
70K miles

2nd Transmission
2nd Passenger side head gasket (And it's leaking again now)
2 Multifuntion switches
1 shorted out wire under the hood
2nd #8 Coil

 

Your problem could be caused by a hose having disconnected from one of the fuel pumps--inside the gas tank. Several 1999 Lightnings(5.4L too) have suffered from this ailment. The clamps are at fault if I remember correctly. It could be the pump(s) instead but you won't know without dropping the tank, although I would think a fuel pressure test would indicate one or the other.

Dan