1999 E 350 Super Duty Class C mtorhome...
Seemed to be starbing for fuel climbing hills in PA.
on way to FL. ..
Started not taking throttle above 1/4 throtle.
Tried to stomp it down to down shift bur really fell on its face...backed off to 1/4 throttle and could make it off hiway.. Towed to grage.. ..
new Mcraft Fuel Pump ...after test drive with P.gauge... (presure dropped to 10 psi when stompped).. perfect. With new pump.
Climbed some big hillsg getting going..
excellent..
150 mi latter... same exact problem.
limped to Ford Dealer.....
Almost put in all new plugs/ coils.. ?
$1949.00 estimate !!...
lukily they held off. No codes! Takes 14mi to get the symptoms.. .. 1/4 throttle ok...more it bogs out.
tried piching return.. NG..
Bad new pump? not venting??
Old sock looked beautiful...
Cat checked fine...no codes. Confusing codes on Ford Diagnostics... nothing solid..
running up $$$$$$$$ Labor / hotel / nerves
hellllllllp !!!
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The fuel pressure should never drop to 10 psi.
Has the fuel filter been changed?
The fuel pump may not be getting enough power to pump.
Have you checked the fuel pump power relay?