mercedesman

have a f150 with above engine the engine will run fine idling all day long when you drive it down the road about 8 to 10 miles the engine starts to run rough stalls shudders.
heres what has been done at this point
engine has been rebuilt all timing componets have been replaced (engine has variable valve timing)
after re intall the engine ran fine run it in road test all ok
customer picks up truck 2 miles down road blowes oil filter off oil over pressures
engine rebuilder picks up truck takes to shop rebuilds engine again re install engine did 40 mile road test in detroit traffic runs fine deliver back to customer imrc acts up customer replaces imrc engine runs fine for 8 to 10 miles acts up again same symptoms run rough stall rattles
rebuild shop pickes up takes back to shop rebuilds again every thing to ford specs reinstalls runs fine for 8 to 10 miles starts same symptoms

all sensors have been replaced twice oil filter blowing off was oil pump over pressure(faulty oil pump new) when rebuilder replaced oil pump he replaced all timing componets again

called ford tech line at ford motor co rebuild shop stepped thru all procedures with them and ford told rebuild shop to put a new engine in it

has anyone had simular troble with ford 5.4 triton engines and any sugguestions will be helpfull

my engine rebuilder is austin jorden they build race engines and have a good rep

we are thinking that we are looking at a pcm glitch but our scanners will not pick up any bad sensors cannot find any broken wires in harnesses or sensors when it acts up it always seems to be the left bank of the engine variable timing controls

thanks mercedesman
owner sugarland motorwerks