2001 Explorer mis firing when hot

[markedman450]

I was thinking of the regulator and also the fuel sending unit. Yea the guys at the garage said they checked it a few times and it was running over 90. I think thats causing it to flood the car and thats why it dies when i try to accelerate hard. I guess ill start with buying a new sending unit and regulator since it could be both and hopefully that fixes it.

 

[cjones101812]

according to my diagnostic charts. if the fuel pressure is over 65psi then replace the Fuel Pressure Regulator in the fuel tank. the mechanic that said it's on the fuel rail may be looking at the Fuel Pressure Pulsation Damper (it has a vacuum hose on it just like the old fuel pressure regulators did)

that is prob with the fuel pressure being so high. i would still have the fuel tank and all components and lines cleaned because of how dirty your fuel filter was.

you or they should check that everything is clean and in working order before reinstalling.

 

[CDW6212R]

Don't waste money on the sending unit, that is just for the gas gauge. Definitely be sure that the lines and filter are clean, that might have begun the problems.

 

[markedman450]

Change the filter every 6 months, just did it again few weeks ago. So the winning idea is the fuel pressure regulator? Hopefully thats the problem, plus ill have the lines cleaned, tank cleaned and new filter on anyway.

 

[markedman450]

Well no parts dealers around my area even carry the fuel pressure regulator. I called a Ford Dealer and they have it but for 175. They also say that its not by the pump, he said there is a box that attached to the purge canistor but the actual fuel pressure regulator on my 01 SOHC 4.0 engine is on the fuel rail...So now i dont know what to buy haha. I dont have a pressure gauge so even though i can install it if its on the fuel rail, ill have to have a garage do it so they can adjust or check the pressure. ANyone have any ideas if its actually by the pump or the fuel rail?

 

[cjones101812]

according to my data:

a 2001 Explorer Sport 4.0L SOHC uses a MRFS (Mechanical Returnless Fuel System). MRFS does not return fuel to the tank by means of a fuel return line. The fuel pressure regulator is mounted on the Fuel Pump Module located in the fuel tank. Excess fuel is returned from this point.

 

[markedman450]

Thanks, yea i checked everywhere and no one seems to sell it. Ford Dealer is saying its in the engine bay and local garages are saying its by the fuel pump and when they order a fuel pump assembly it comes with it. All i know is the problem happens here and there, not all the time. I just took a small drive maybe 20 minutes on the highway, and it go to the point where i couldnt go into a passing gear without it bucking, then 10 minutes later it got to the point where i had to pull over because even if i touched the gas it would not move, it felt like the engine was about to stall and it was misfiring. so i pulled over, waited 2 mintues started it back up and it ran fine the next 5 minutes home. This problem is driving me nutz

 

[cjones101812]

"KEY OFF. For Mechanical Returnless Fuel System with fuel pressure greater than 448 kPa (65 psi). REPLACE fuel pressure regulator in fuel tank."

That is from a FORD Tech CD. the same cds that the ford techs use.

that ford parts person doesn't know what their talking about. try a different dealer.

what your local garages are saying is correct. it should come with the fuel pump assy.

 

[markedman450]

When you say key off, does that mean to check the pressure when its off? I know the garage said they checked it a few times so im sure they did it the right way, but yea they said it wasnt low like they expected it to be, it was really high, like around 90-92

 

[CDW6212R]

We'd all like to have it fixed quick, but with so many people like the dealer not knowing their job, I wonder about the pressure still. I would be hunting a used assembly from another truck, they don't go bad often. Can you possibly have the pressure checked elsewhere? Don't pay $175 for a simple part like the FPR that in aftermarket is $90 new.

Your fuel should be clean with the changed filters and when the tank is out(it will be obviously clean or fouled). If you trust the checked pressure then get a different FPR on it soon.

Does anyone know what the small contraption on the fuel rail really does? I have never heard a reasonable answer. It is not a pressure regulator after 1998. Regards,

 

[cjones101812]

When you say key off, does that mean to check the pressure when its off? I know the garage said they checked it a few times so im sure they did it the right way, but yea they said it wasnt low like they expected it to be, it was really high, like around 90-92

no, i copied the entire line. i should have removed key OFF, the previous step to get the fuel pressure had the key ON so after the test you would turn the key OFF.

should be: "For Mechanical Returnless Fuel System with fuel pressure greater than 448 kPa (65 psi). REPLACE fuel pressure regulator in fuel tank."

 

[cjones101812]

Does anyone know what the small contraption on the fuel rail really does? I have never heard a reasonable answer. It is not a pressure regulator after 1998. Regards,

Fuel Pressure Pulsation Damper: Description and Operation

FUEL RAIL PULSE DAMPER

The fuel rail pulse damper (Figure 71) located on the fuel rail reduces fuel system noise caused by the pulsing of the fuel injectors. The vacuum port located on the damper is connected to manifold vacuum to avoid fuel spillage in the event the pulse damper diaphragm were to rupture. (The pulse damper should not be confused with a fuel pressure regulator, it does not regulate fuel rail pressure.)

 

[CDW6212R]

Okay thanks CJ, it's just a (fit and finish, noise/harshness) contraption, good.

 

[markedman450]

Well i ended up having the regulator replaced at a garage since i was at a wedding all weekend. Pick it up this morning and take off, seems to be running good. I go to turn left and the whole front end starts shaking like a tire is about to fall off. I take it back and the one mechanic is saying they prob had to drop the rear axel to take the tank off and if the mechanic put it back in wrong it could be causing the front axel to now shake...all i know is right hand turns it wants to buck bad.....haha what else can happen

 

[CDW6212R]

Well the story of the rear axle was a lie, dropping the tank has nothing to do with any other parts. I hope you figure out that new symptom soon. How is the engine running now, and did they tell you what the fuel pressure is now?

 

[daffy]

Is the steering wheel 'fighting' you?

If so, maybe for some reason they jacked with the front wheels while the vehicle was off, and got air in the power steering rack.

Try going slow in a parking lot, doing lock to lock turns, 3 lock to lock turns usually gets mine cleared out.

 

[CDW6212R]

Good call, that is the symptom of air in the steering system.

 

[markedman450]

Its not fighting me at all. I just have a huge vibration coming from the front when i try to turn it right at a certain position. When i went onto the highway i thought a tire was coming off, almost felt like the axel was binding. It ran perfect steering wise when i brought it to them so i dont see how something just broke.

 

[CDW6212R]

Do check the power steering fluid and level. How does it look, full and clean?

 

[markedman450]

Yea its full, and it was running perfect when i dropped it off two days ago at the garage... So unless they did something while changing the fuel pump, etc. It feels like the front axels are binding and the wheels wanna come off. The one mechanic said that if they dropped the rear and didnt install it a certain way to align with the front it can cause problems but i have no idea...