I have a 1997 F250 HD with two wheel drive, an automatic transmission, and a 5.8L that is fuel hydro-locking the number 8 cylinder when cranking to run. The fuel has been entering the block.
This is what I done so far:
Removed the oil pan, cleaned out the oil /sludge, (truck sat for a bit without oil it hardened in the pan.) replaced the oil, filter and oil pan gasket.
Replaced all of the fuel injectors with rebuilt units. Tried to start the truck, never started, then still the fuel is completely hydro locking the motor in the #8 cylinder.
Removed the spark plug, cranked the motor to drain the fuel.
With the spark plug removed, unplugged the injector, cranked the motor and fuel filled into the #8 cylinder. The coil wire was unplugged.
Removed all of the spark plugs, turned the motor by hand to drain the cylinders/check. Found fuel in the #8. The coil wire was unplugged
Replaced the #8 injector with an old unit. Installed all the plugs, plugged in the coil and cranked to start. Motor started, ran badly for less than 5 seconds then died. Cranked the motor sever more times, motor once again hydro locked. Removed the spark plug and fuel leaked out of #8 cylinder. Turned the motor by hand to drain the fuel.
My question is what is the problem and how do I fix it? Thank you I am lost…

 

What is the fuel pressure after two or three key on cycles? should be around 40psi.
If it is much higher, it could be blowing thru the injector, though it is uncommon.
Get a noid light and hook it to the injector plug. turn the key on. It should not light up. Crank the engine and it should flash as the engine cranks.
If the noid light lights bright and steady, you have a bad injector driver in the ECM and the ECM will need to be replaced or repaired if you know someone good at repairing electronics. I have had two different Fords have an injector driver do this.

Not sure if it will help, but i's a good place to start.

 

Hi...
Thats why I unpluged the injector still fuel went into the cylinder. I will check the pressure.
Thanks

 

Sounds like you have a bad Fuel Pressure Regulator (FPR).
Take the vacuum line off the nipple on top of it and see if you see any fuel.
It might help to turn the key on and off with the vacuum hose off of the Fuel Pressure Regulator.
If you see any fuel at all the Fuel Pressure Regulator is bad and causing your problem.
The fuel will be coming out of the nipple on top of the Fuel Pressure Regulator.

Nipple on top = Engine Vacuum Reference Tube

FPR Location:


FPR:


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I wanted to thank everyone that has contributed their expertise on resolving my problem.
THANK YOU!!! THANK YOU!!! THANK YOU!!!
I have solved this problem and discovered a new problem.
The old problem was the Fuel Pressure Regulator, the diaphragm must have been ripped, and fuel was entering the vacuum line and feeding back into the intake and then running into the #8 cylinder.
My new problem must have been created by the fuel hydro locking the motor. Upon starting the motor I soon realized large amounts of white smoke coming from the tail pipes. Yep, antifreeze/water in the exhaust, so it seems to me, I now have a blown head gasket. Once again, THANKS EVERONE for the help, I now know what I will be doing for Thanksgiving.

 

Glad we could help. Sorry to hear about the head gasket. A little harder to change than the fuel pressure regulator

Happy Thanksgiving