Ok so I have a 1997 Ford Explorer with the 4.0 SOHC .
The girl that owns it went out and started it to warm up and went back in the house , when she came back out it had died and wouldn't start .
I hauled to our shop and started diagnosing it .

It has spark
has fuel
Timing is good
Fuel pressure regulator is good
Crank sensor is good
About 62 PSI fuel pressure
No CEL

Seems to be getting WAY too much fuel and fouling plugs !
Replaced ECM ...same thing .
used NOID light on injector wire and I have never seen one get so bright !

Any Ideals ?????

 

You might confirm that she filled it with the correct fuel (and not from the yellow handle pump). Also confirm that the truck with fuel hasn't been sitting all summer and fall until the weather started getting cold (old fuel).

Is the noid light flashing at what seems to be the correct rate? Do you have an oscilloscope that you can use to measure the fuel injector pulse width? Maybe the noid light is getting bright due to the duration of pulse rather than the voltage of the pulse. Since you mention that it seems like it's getting too much fuel, it sounds like you've confirmed the injectors are at least allowing fuel in to the cylinders, correct?

-Rod

 

We had initially thought about bad fuel (although this is her daily driver) Fuel smelled bad so we drained the tank and put 5 gallons of fresh fuel in it .

noid light seems to flashing as it should ,just really bright . Pulled intake off and cranked it and injectors are dumping a ton of fuel into the motor .

No oscilloscope availability

It is defiantly getting fuel into cylinders , plugs are covered in gas after a couple seconds of cranking .

 

Power to the fuel injectors is direct battery voltage via the PCM Power Relay. Have you checked the charging system voltage to make sure you don't have some good over voltage condition? I'm not sure how that would happen though since the engine isn't running, unless some accessory is plugged in that is providing excess voltage with a pretty high current capacity....

Also, make sure the Engine Coolant Temperature (ECT) sensor is reading close to where it should be for the temperature of the coolant, as well as the Intake Air Temperature (IAT) sensor. Either of these sensors being out of specification could lead to a flooding condition.

If you crank the engine for a few seconds, then hold the accelerator all the way to the floor ("Clear flood" mode) will the engine start?

-Rod

 

Isn't 62 psi on the high side? Off the top of my pointy head, I seem to remember that it should be 45ish psi, but that may be what I remember for my '91 Ranger and '95 Aerostar. I tried to look up the value in my '98 manual, but it refers to the powertrain/emissions manual, which I don't have.

As far at the regulator being good, I assume you mean the diaphragm isn't ruptured?

How are the temp sensors - intake air and coolant? Do they read correctly?

Is the MAF sensor clean/good?