Fuel pressure too high? Pressure Regulator?

[genesiss]

2002 ford sport trac, fuel pressure 60 psi at on position and 65 psi at idle. Poor fuel economy rare cases of stalling and too much much fuel in system indicated by one incident of black smoke and rough idle that cleared after a restart. When stalled take an hour for issue to clear itself. Could it be a sensor or perhaps the fuel pressure regulator? Any insight would be appreciated, I also am having some difficulty locating the fuel pressure regulator.

 

[James909]

Those pressures are fine for the returnless style system that's in your truck. So I don't think it's the FPR, which is integrated with the fuel pump by the way. Is the check engine light on?

 

[genesiss]

There are no check engine lights at all or at any point. So is it normal for the fuel pressure to drop quickly when the engine is turned off after just running? It dropped from 65 psi to 58 psi within 45 seconds and seemed to stay around 58 psi.

 

[manaen]

how long does it take to loose all pressure in the fuel line?

Do you have the returnless system (IE: one line from the tank with no line returning ) ?

I thought they were only on a few select gen2's like my 2001. anyway if you do then 60psi is normal. If you find that the pressure is dropping fast when you turn off the truck you could have a leaky or stuck injector.

How many miles do you have on the clock?

 

[genesiss]

There is a return line on the fuel system back to the tank. The truck has 120,000 miles on it. 65 psi solid running, about 55 psi in the on position unless i turn the ignition on and off a few times then its about 60 psi. Pressure drops within a minute after turning off the truck when running at 65 psi down to about 58 psi.

 

[genesiss]

I also noticed a recent issue with the gas gauge jumping and moving alot with hard turns and stop and go traffic.

I dont think I have a flex fuel module but I have heard that can be responsible which just so happens to be part of the fuel pump just like the FPR. Is it possible this is all connected?

I really want to avoid replacing such an expensive unit like the fuel pump assembly unless im sure thats the issue.

I also have considered the possibility of a flooding fuel injector gone bad for the rare intermittent stalling issue and a recent problem with black smoke that cleared itself after being turned off then back on unless its the temperature sensor that may be causing flooding?

Is there a simple way to diagnose which injector may be bad?

Does anyone have the specs to see how much pressure drop is allowed over a given period of time?

 

[manaen]

if you have the system with a return line and regulator on the fuel rail 65psi is WAY too much fuel pressure. You may want to disconnect the vacuum line to the regulator and re-run the test see if anything changes. At those pressures you should be noticing black smoke from your exhaust. In fact the back of your truck should be showing signs of blackening, and your MPG should be way down. If you have the return style system your fuel pressure should be somewhere around 35psi.

 

[genesiss]

Thank you for taking the time to reply, i assume it is a return system based on the two lines from the tank however i have found that the pressure regulator is in the tank with the fuel pump assembly. No sign of blackening and only one incident of black smoke that resolved itself with a restart of the engine. City travel aprox 12 mpg and highway is about 19 mpg.

 

[elvinenn]

how to test or replace the fuel pressure regulator on 1996 4.0 explorer

 

[CDW6212R]

All 1999 Fords and newer have one fuel line, they are returnless and 62-65psi is the proper pressure all of the time. If the pressure doesn't drop to zero in a very short time when shut off, it should be fine. Night,

 

[Fireside3]

All 1999 Fords and newer have one fuel line, they are returnless and 62-65psi is the proper pressure all of the time. If the pressure doesn't drop to zero in a very short time when shut off, it should be fine. Night,

Actually, hold pressure should be minimum of 30psi before 5 min has passed or you have a leaky fitting, leaky injector, defective fuel pump, or defective fuel pressure regulator.

 

[Phreaq]

The manual for the Fuel Pressure Tester Kit (by actron) states 35-60 psi for 2001 Explorer and sport-trac 4.0 vin E

The vehicle I am working on has 70psi!
I suspect the FPR in the tank.

 

[Phreaq]

Specs from Alldata
2002 Ford Explorer sport-trac 4.0 vin:E
"Fuel pressure 30-65 psi flow rate 24lbs/hr"
"Includes USPS Explorer model"

 

[CDW6212R]

The manual for the Fuel Pressure Tester Kit (by actron) states 35-60 psi for 2001 Explorer and sport-trac 4.0 vin E

The vehicle I am working on has 70psi!
I suspect the FPR in the tank.

Specs from Alldata
2002 Ford Explorer sport-trac 4.0 vin:E
"Fuel pressure 30-65 psi flow rate 24lbs/hr"
"Includes USPS Explorer model"

Don't rely on aftermarket data, those specs are wrong.

The pressure is 35-40psi before 1999. From 99 on it's 62-65psi, the former with a larger variance due to the vacuum of the FPR.The injectors(pre-2002) are also not 24lbs/hr. Those specs are a poor mixture of old and new model information.

Rely on the information that you find here, we know these vehicles better than the book writers.

 

[Phreaq]

30-65 looks wack to me but im only worried about max.

Rely on the information that you find here, we know these vehicles better than the book writers.

I have seen more then one post stating fuel pressure of 72psi is normal. So I went to alldata because I have been using it for 6 years. I got fuel pressures for 2000-2002 and the 00 01 look like a scan from Ford covering all motors (car and truck) with part numbers. 02 is Alldata format for the vehicle currently selected.

I'm calling this FPR bad due to 70psi pressure and p0175 p0172 - rich both banks
EDIT:Well so much for my pressure tester. I got another gauge on it and its KO jump the relay pressure is 62psi, running pressure is 66psi .... I thought i started my own thread the other day but i must not have submit it.

 

[Fireside3]

The manual for the Fuel Pressure Tester Kit (by actron) states 35-60 psi for 2001 Explorer and sport-trac 4.0 vin E

The vehicle I am working on has 70psi!
I suspect the FPR in the tank.

On my 01, the FPR is mounted to the pump/float assembly in the tank, and there is a device similar to a FPR on the back of the DR. side fuel rail, but that is apparently a fuel pressure "dampener" to absorb shock of high fuel pressure hitting the rail.

 

[Floridaexplorer43]

I'm showing 65 psi + idle on a 2003 with 4.0. My long term fuel trims are both -9 or -11

 

[koda2000]

Check your fuel filter. Does it have 2 ports on the rear of the filter and 1 on the front? Some Explorers (like my '01 Sport Trac) used a 3 port fuel filter. Looking at the fuel tank it may appear that there are 2 fuel lines attached (a feed and a return) but this is not the same as a return-style fuel system. I have no idea what the 3 port fuel filter is supposed to do for you and not all '01 ST's had a 3 port fuel filter. All my other Explorers and Mountaineers ('97-'01) use the 2 port fuel filter and only my '97 had a return fuel line. I believe Ford went to a return-less fuel system beginning in 1998 or 1999.

 

[Floridaexplorer43]

I bought the 4 door Explorer with 170,000 miles put about 8000 miles on it, no idea if precious owner changed filter ever. My understanding is there is a cover for the filter (a heat shield ). Would filter give negative ltft?? My understanding is negative ltft is a rich condition so it's taking away fuel, correct?

 

[Floridaexplorer43]

If harbor freight gauge is showing 65 psi at idle, is my filter in need of change? Others online have reported 65 psi as well at idle. It took about an hour last night to drop to 40 psi.