A few weeks ago I swapped a normal 3.0 engine out of an 01 4wd ranger into a 1999 3.0 Flex Fuel ford ranger 4wd. All of it went great and got it all finished and it cranked right up and ran fine, just a few adjustments here and there. A few days later I crank it up and move it to mow the lawn and when I finished it wouldn't start. I've replaced the injectors, fuel pressure regulator cleaned the fuel rail and many other things, but nothing has worked. The symptoms I'm getting are it will turn over but simply won't crank, the only code I have received it the code for the flex fuel sensor so I changed the computer and nothing has worked. I've tested the fuel pressure and with the key on the highest it will go is to 50 psi no higher there is also fuel getting into the oil. Any help would be appreciated thank you.

 

Welcome to the forum

Fuel system for '99 Ranger would have 60-70psi normally

And fuel in the oil means you have liquid gasoline running into the cylinders and down past the rings.

So either one or more fuel injectors are opening or stuck open, or pulse damper vacuum hose has fuel in it, its leaking.

I assume if you take the air tube off the intake manifold and open the throttle you can smell fuel, if you haven't done this try it.

If you don't smell fuel then spray some fuel into the intake and try to start engine
If it starts and dies then spark is OK and yes, fuel is the issue
If it doesn't start then you have no spark
That's is the 50/50 test, always first test to do anytime there is a no start

Pulse damper is at the end of the fuel rail, it will have a vacuum hose attached, remove that hose and check it for fuel, if fuel is in there then damper is bad.

The fuel injectors all get 12volts when key is turned on, the Red wire on each injector
The computer Grounds the other wire to open that one injector, so there are 6 Ground wire that run back to the computer.
If one is shorted to ground then that injector would open when key was turned on.

There is a simple test, all fuel injection computers have a way to shut off fuel injectors when cranking engine(starter motor turning engine)
Clear Flooded Engine Routine
Turn the key on
Press gas pedal all the way down to the floor and HOLD IT DOWN
That will start "Clear Flooded Engine Routine", computer will not Ground any injector until gas pedal is released

Now when you try to start engine it will not start, it will have spark but no Fuel, injectors are off

This can be handy when looking for leaking injector

Try the test, if engine fires even a little you have a leak
Now unplug the coil pack, 4 wire connector, so no spark
Do test again but crank it a few times gas pedal DOWN all the way do not let it up

Now pull spark plugs
They should ALL be dry, the wet one(s) have the leaking injector(s)

 

We changed the injectors with newer ones, only difference is that the original has three holes fuel flows through, the new ones have four. And they came off an 05 ford car with a newer 3.0 with a plastic intake manifold, the engine was also side mounted. Is it possible that 1 of the cylinders is sparking but the rest aren't, I pulled the wire off the engine and put a screwdriver in it and it sparked, we've changed the fuel damper, and nothing happened. Still only 50 psi in the rail.

 

Just turning the key on and off causes a spark, doesn't mean much.
A coil sparks when you CUT power to it

50/50 test tells you if spark is strong and at the right time, and very very simple to do

 

We did the 50/50 test, and it ran on eythr, then we tested and outside injector that was not attached to the engine, it seemed to function fine so we decided to hook that same injector to the wiring on the truck and then it didn't work, any ideas? We tested for 12 volts and it was there, we then tested the pcm ground and it was not there.