2.3 low fuel pressure need help

[dangerranger83]

I've heard of this kind of thing happening to a truck and a boat. It had to do with the fuel lines and the fuel rail. The boat engine would run fine but when you went to give it gas it would only be able to run so fast before it cut out. Turns out the inside of the fuel lines where fraying and creating a flapper valve kind of deal that restricted the fuel flow. As for the truck it used a plastic fuel rail and the same thing had happened on the inside of the fuel rail.

How old are the fuel lines on your truck? You've replaced almost everything in the fuel system othe then the lines from what you have said.

Have you also checked the voltages to the pumps?

 

[SMTGREG]

With the fuel pressure gauge connected. tape the gauge to the outside of the windshield and road test the fuel pressure should stay within 5 lbs of idling during hard accel. If not you have a restriction in the fuel system. Not enough volume or flow.
When turning the key to on position the pumps should run about 3 seconds then stop. does the fuel pressure hold for at least 1 min. With the engine cranking or running the pumps should run continuously. Another problem could be low voltage to the pumps while running. The voltage at the pump when RUNNING should be with in .5 volts of battery voltage. In other words if the voltage at the battery is 14.2 volts the voltage at the pumps should be 13.7 or more. Also the voltage on the ground side of the pumps should be less than .5 volts.

 

[horsepower]

with key on motor off the pumps will run non stop. 32# of pressure is all I get with key on motor off. with motor running I only get 22# of pressure. The only thing I didnt replace are the injectors and the lines. I will check pump voltage tomorrow. All the trucks and all my years and this one has me stumped. The guy I bought it from was stumped to thats why he sold it so cheap.

The other thing that has me stumped is when i plug in the code reader it does not register that its plugged in at all. yet it works fine on the escort.......

 

[horsepower]

Tested everything came up with no more than .5 volt drop. Also you can hear the fuel pumping through the rail! its like the fuel pressure regulator is not working at all. it was doing the same thing before i replaced it as well. Now when i pulled out the old regulator there wasnt anything under it. I almost expected to see a spring or something in there (like a valve the regulator would operate) so i assumed that was the way it was supposed to be. The P.O. did rebuild the motor so I'm not sure if anything on this truck is right.

On another note...... the fusible links on the drivers side (under hood) are all wired together. Does anyone have a pic of what the harness should look like? They are right next to the washer fluid box. I dont think this is the cause of my trouble but it couldnt hurt to fix it right......I can email or text pics.......

Thanks everyone for the help!
Hp

 

[horsepower]

one more thing...... The old style fuel filter canister is mounted behind the fuel pump on the rail. could this thing be causing a problem? and is it ok to get rid of it since it isnt needed? The fuel filter is in front of the pump on the rail......

 

[hartwrenches]

fuel pressure

Get some line/hose pliers and add your own restriction to the return line. If the pressure gos up then return is the problem.

I have a few fuel rails, I'll take one apart and check, but I'm pretty sure there's suppose to be a rubber diaphragm type thing between the rail and the regulator to control flow.