I have an 1996 F-250 with the 7.3 PSD. It has 220,000 miles. I am experiencing a loss of power. It seem most dramatic when going up a steep hill. Sometimes after the loss of power speed will even decrease going down the hill after passing the crest. The truck has two tanks and it seems to happen on either tank. If I shut off the engine and then restart it it seems I have adequate power. Can't tell if it really has the power it should. Is there a screen in the system somewhere that may have crud in it that should be cleaned. I can't believe both tanks screens would be plugged and act the same. Thanks in advance for any ideas.

PS I have changed the fuel filter twice and the oil was changed less than 1000 miles ago and is still clean.

 

FPR screen is inside the fuel filter bowl on the right side in a little hole. Take the cotton off of a q-tip and clean the gunk out.

Also, check your fuel pressure at the FPR (brass thing on the right side outside the fuel bowl). There's a schrader valve on there that you can put a tire gauge on to check. Make sure you get one that goes up to at least 80psi.

Your fuel pressure should be between 45psi and 75psi at idle.

If it's low you can do the FPR shim where you take the big nut off of the FPR, take the spring out, put a BB (like from a BB gun) in, then put it back together the way it came apart. Should boost your pressure by about 15-20psi. Just don't have it higher than 80psi at idle.

 

You can also try unplugging the MAP sensor to see if it runs better, or unplug the ICP sensor and see if it runs better.

 

I will check out as you suggested. Where are the connections to the MAP and other sensor?

 

Map Sensor ...



ICP Sensor ...

 

Thanks. I will check it out.

 

I checked the fuel pressure. It is 50psi at an idle. I goes down to 30-35 psi at 1500 rpm. Is that right or should the pressure stay up. The pressure gauge needle wiggles I assume that is from the pump.

Does anyone have a picture of the FPR and how to clean and or shim the spring?

 

Go here, post #8 ... https://www.ford-trucks.com/forums/6...-pressure.html

Remove the nut.
Inside there will be a spring.
Remove the spring.
Insert BB where the spring came out.
Put the spring back in.
Install the nut, make sure the tit on the nut goes inside the spring.

 

Thanks. I'll check it out.

 

I cleaned the screen from inside the fuel filter housing. I then had fuel pressure of 50 psi at idle and 40 psi at 2000 rpm. It seemed to be better in the shop. I then drove it and the same thing, loss of power. I then figured out how to leave the gauge on by running is along side the hood. When for a drive, same thing. Pressure would drop to zero! Came back and pulled the FPR off and cleaned the screen. Some gunk, not a lot. When for drive same thing. Pressure would drop to zero at 1500 rpm in third gear, loss of power some missing. Letting the truck set and idle pressure would gradually return to 50 psi.

I haven't tried the shim yet. Looks like the fuel pump? I did both tanks so unless there is something that could get plugged in the fuel system it looks like the pump to me.

 

Wow, 0 PSI is not good... I'd put my money on the pump at this point. I don't think the shim is gonna help you much. Is there any fuel leaking from the weep-hole in the actual pump?

 

My buddies truck was doing the same thing the other day losing fuel pressure... Check the filter to see if there is any odd colors or gunk... He had algae in his tanks and lines and some how it was expanding to block the flow with new lines and cleaned out tanks his truck is 100%... Took us two weeks to figure this one out and he is tech for international dealer lol...

 

I have installed two new filters. The one in there now looks good. No goop or other stuff on either filter when it was changed. The screen had some fiberous black stuff. Didn't look goopy like algae. I don't thinkit was plugged but can tell for sure since I tried cleaning it first from the inside of the fuel filter housing. Bottom of bowl was clean. I think I will get a pump and put it in and see what it does. What should be the pressure range on the fuel when running and going down the road?

 

I'm not sure on the pressure while driving.

I just know that optimal pressure at idle is between 65 psi and 75 psi. You don't want it over 80psi as you can blow out o-rings.

 

If and when I get it fixed I will post the pressure ranges I have when it is working correctly. I am going to wait on the shim until I get a new pump in there as the pressure may rise with the new pump.

Thanks for all of the suggestions!