code P0455 stored, has hard start, bad hesitation on accel. new plugs, wires, coil, injectors and fuel filter. all factory parts. better but not 100%. fuel pressure good. pos vac leak or just normal air flow through the upper plenumm ? floods easily, running rich, gas in oil. (like float stuck on a carb) have seen threads on pressure regulator, upper intake gaskets. ford says they have updated fuel fump for hesitation, but may not fix hard start, flooded condition. any suggestions ??

 

gas in the oil? how could you tell? most common fix for p0455 is a loose gas cap. could also be a bad fuel pressure regulator or vent hose. gas in the oil can be caused by bad upper intake gaskets causing fuel to enter directly in to the crank case ventilation area then in to the oil. this is common with explorers, especially old ones. i'd be willing to bet its a 6 cylinder. your symptoms are classic for a bad upper intake gasket.....

 

thanks for info. that's where we are headed next. will give u update on monday

 

new injectors, ckp sensor and fuel pump. same problem. does not run any better with maf unpluggged. hard start, seems flooded, falls on its face on accel. puzzled that o2 sensors, long and short fuel trims ok. no codes set, using modis 9.2 as diagnostic tool, mode 6 diags no help. almost cant see the forrest for the trees ? any help, suggestions appreciated...

 

You mention these values are good, but could you quantify:
KOEO fuel pressure =
KOER fuel pressure =
O2 Sensor B1S1 =
O2 Sensor B1S2 =
O2 Sensor B2S1 =
O2 Sensor B2S2 =
STFT bank 1 =
STFT bank 2 =
LTFT bank 1 =
LTFT bank 2 =
And not previously mentioned as considered:
ECT voltage or temp when cold =
ECT voltage or temp when at operating temp =

-Rod

 

have you bothered to take the upper intake off and check or replace the gasket? that is an easy thing to do. replacing the injectors is far more difficult. that'd be where i would start.

 

new upper intake gaskets with new injectors. still the same. not at shop now, so specs are from memory only (not the best at my age, sorry)
new fuel pump also in truck.

koeo pressure = 35
koer pressure = 45
b1s1 = 170-775 switching
b1s2 = 170-770 switching
rear o2 sensor (only one on truck) fixed at 500 mv
stft bank 1 = 0
stft bank 2 = 1
ltft bank 1 = 4
ltft bank 2 = 2
ect cold = 75
ect hot = 170
timing at idle = 15 ? is this correct ?


new crank position sensor also installed

 

Don't drive the vehicle again until you change the fuel pressure regulator. And buy one from Ford. You are getting fuel in your oil from the regulator vacuum hose and it is washing the cylinder walls with raw gas. This will quickly dilute the oil and you can spin a bearing.

 

sounds like that could be it. The regulator is not in the tank on these trucks right. it is on the fuel rail or around there. if he puled the vacuum line off of the fpr it should be obvious. I would have thought with all the work done already that he would have done that.

*maybe the regulator is in the tank. He said he changed the fuel pump I wonder if he changed the regulator too. These people cant even create a detailed profile of their truck ......

 

The FPR is on top of the engine by the fuel fail. It has a diaphragm in it that will leak and let raw gas be pulled directly into the intake manifold where it will cause a rich fuel mixture. With the engine shut off, the fuel pressure in the fuel system will bleed through the FPR and into the intake, through open valves and into the cylinders where it will run passed the rings and into the crankcase. Fuel in the cylinders will also cause the hard starting.