HoJoF150

My 2001 F150 4.6L misses under load. There's no computer record and
the dealer can find nothing wrong.

tex95bird

How many miles? My experience is that O2 sensors can cause this. If
you have over 80k miles it is a possibility.

Leroy


--
tex95bird
------------------------------------------------------------------------
tex95bird's Profile: http://www.usenetcars.com/member.php?userid=1901
View this thread: http://www.usenetcars.com/showthread.php?t=245611

Wendy & John

"HoJoF150" wrote:

My 2001 F150 4.6L misses under load. There's no computer
record and the dealer can find nothing wrong.
__________________________________________________

A miss under load conditions is often the result of an insulation
breakdown under the higher spark plug voltage needed at high
manifold pressure. Wipe the dirt off of everything subjected to
high voltage (plugs, boots, plug wires, coils, distributors, etc.)
and inspect the parts for burning, cracking or other failure.

Sometimes you can see a voltage leak by duplicating the driving
conditions: Place the truck's front bumper against a solid wall
and have a friend run the engine under load while you look into
the engine compartment for high voltage arcing. Do this in a
totally dark area so you can see small arcs.

Good luck.

Wendy & John.
___________________________________________________

F.H.

HoJoF150 wrote:
> My 2001 F150 4.6L misses under load. There's no computer record and
> the dealer can find nothing wrong.

If it's pinging (more like a grinding sound) it's the MAF. I recently
had this problem and it was caused by a small water leak around the
thermostat. The water would run straight back and into the plug wells.
I would wait until it cooled a bit to check under the hood and by then
it was dry. Pull all your plug boots and check for moisture?

ankhe105

F.H.!!!! Sorry to butt in here but trying to contact FH about manifold
recall. Thanks, Doug

F.H.

ankhe105 wrote:
> F.H.!!!! Sorry to butt in here but trying to contact FH about manifold
> recall. Thanks, Doug
>

Been discussed here a lot. Not sure what the criteria is that the
dealers use. I received a warning by mail telling me what to do if it
blew. Post a question about 4.6 manifold warranty's and someone will
help I suspect. I recall a lot of discussion and a lot of anger. Most
weren't covered.

Frank