Fuel Pressure Regulator...?

[Expl01]

Hey everyone,

My engine will not start and I need help.

It is a 2001 XLT, 4.0 V6 SOHC, A/T, 2WD

The engine will not start apparently due to excess gas [massive “flooding”]

So far I have found the following:
It cranks strong, so battery, starter & ignition all work well.
It has spark at the plugs
It has good compression
The timing is correct.
The plugs were wet when I pulled them
There is a strong smell of fuel when it is cranked even for a few seconds
There was liquid gas at the throttle body hose connection.


If I have a bad Fuel Pressure Regulator that is causing flooding so that the engine will not start [and yet sets no codes?], is it possible to add an aftermarket FPR in the line between the fuel filter and the Schrader valve?

I am thinking that if the stock FPR is causing too much fuel, then it has failed “open” and there is always too much pressure [I have recently replaced the Fuel pump, so this is near new and should last several years], as opposed to not enough pressure or no pressure. Since it will always have more than enough pressure, what can it not be controlled by a secondary FPR installed into the line. Why? Well this would not only save me pulling the tank to change it [since I have a 2001], but it will save me the $300+ it will cost to get the whole module from either Ford or the parts stores, which offer the same type of replacement at a similar cost.

I am hoping for some insight or experience from anyone who has any familiarity or exposure to these things or similar problems. Any suggestions will be greatly appreciated. I understand Carburetors [like Holley double pumpers], but if this is a learning experience, I must be a slow learner.

Have a happy Fourth of July, Happy Birthday America!

Jake
01 XLT
GT-350

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[2000StreetRod]

No return path

With the type of fuel pump used in the Explorers I believe a fuel pressure regulator requires a path to return excess fuel to the tank. Your 2001 is a returnless system. The fuel pressure regulator located in the fuel tank allows return of the excess fuel without an external path.

I suggest borrowing or purchasing a fuel pressure gauge (Harbor Freight has an inexpensive but adequate one) to determine if the pressure is excessive. Mine runs about 65 psi at all engine speeds.

Were all of the spark plugs wet? That would eliminate a leaking injector since all would not start leaking at the same time.

Have you cleaned the MAF sensor? If it is oily or dirty the PCM may think the air flow is larger than actual and increasing the injector pulse width accordingly. Make sure the air filter is clean and the intake tubes are not blocked which would result in an excessively rich mixture.

If the engine coolant temperature (ECT) sensor is defective the PCM may think the engine is cold and increase the injector pulse width to compensate for an erroneous engine temperature.

Did you check the compression of at least one cylinder on each bank?

 

[2000StreetRod]

bad fuel?

When you drained the fuel tank to replace the fuel pump was it rust colored or smell like lacquer? You may be fighting bad fuel coming from the tank.

 

[tgreene92]

i just had a very similar problem, double check your compression tests, id get a good reading one second and a bad reading another, turns out the piston rings in mine were shot. i rebuilt the injectors, changed the plugs and wires, replaced the regulator, swapped the maf for a good one. all theses things helped a little but still led me to comclude the rings were no good. check the pressure in the lines, rerun compression tests, and run a full process of elimination.

 

[ranger7ltr]

If I have a bad Fuel Pressure Regulator that is causing flooding so that the engine will not start [and yet sets no codes?], is it possible to add an aftermarket FPR in the line between the fuel filter and the Schrader valve?

I am thinking that if the stock FPR is causing too much fuel, then it has failed “open” and there is always too much pressure [I have recently replaced the Fuel pump, so this is near new and should last several years], as opposed to not enough pressure or no pressure. Since it will always have more than enough pressure, what can it not be controlled by a secondary FPR installed into the line. Why? Well this would not only save me pulling the tank to change it [since I have a 2001], but it will save me the $300+ it will cost to get the whole module from either Ford or the parts stores, which offer the same type of replacement at a similar cost.

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So what IS the fuel pressure at the schrader valve? The returnless system is designed to run at a higher pressure than the the return type of system...65-72 psi is nominal and the regulator in the tank only opens to allow fuel bypass back to the tank if the pressure gets over 80 psi...One other question I have is when was the fuel filter replaced last?

And just because the fuel pump is nearly new doesn't mean that it works properly...If the fuel pressure is not high enough, the plugs would be wet and the engine not run...The injectors will still spray fuel and the mixture is just not sufficient to support combustion...

The fuel injection system is not as complex as many make it out to be...As long as the proper volume and pressure of fuel is supplied to the injectors and the timing of the PCM is correct, the engine is as basic as a carbed engine and it makes its own adjustments as the vehicle runs...