Question Oil Consumption

[JRJ04]

so, i plan on trying to get a better measurement of my fuel pressure today...

where can i buy some of that 1/8" tubing and the fittings? I would think i can get the fittings at my local o'rileys, but what about the tube?

Is it the same tube that i used for my boost gauge?

 

[BIG JOE]

so, i plan on trying to get a better measurement of my fuel pressure today...

where can i buy some of that 1/8" tubing and the fittings? I would think i can get the fittings at my local o'rileys, but what about the tube?

Is it the same tube that i used for my boost gauge?

Most any Parts place should have it. (NAPA comes to mind) And Yes it's the same size as the Boost line, fittings too.. but needs (duh) to be Diesel Fuel Friendly.

Yer call JR.. but you might wana take the FPR apart, and look for the obvious.. first ??

 

[JRJ04]

Most any Parts place should have it. (NAPA comes to mind) And Yes it's the same size as the Boost line, fittings too.. but needs (duh) to be Diesel Fuel Friendly.

Yer call JR.. but you might wana take the FPR apart, and look for the obvious.. first ??

yea, ill end up doing that too. I just think my method of measurement might be off considering the potential for the line to be expanding with pressure. So this hose...is it rubber or is it the hard plastic?

 

[BIG JOE]

The hard stuff. tell the parts guy what yer doing.. he'll know.

 

[JRJ04]

Fuel Pressure

Well, I ended up getting around to attempting to get an accurate reading of my fuel pressure...

Even with the 1/8" tubing (and a shorter length at that)...I still got 38 psi of pressure. It ended up settling at about 40. I went and drove it and had the gauge sitting on the windshield. All was fine and it remained stable. When I nailed it...the pressure dropped nearly 20 psi down to about 20 psi from 40 psi.

After that, I went ahead and took apart the FPR to have a look. First, it looked ok, then after closer inspection I saw that there is some sort of black o-ring type fitting that goes around the brass sleeve that then sits inside of that little ring, that then sits inside the fuel bowl housing. (Mouthfull, but make sense?) That little o-ring was ripped/degraded. Everything else looked fine (main o-ring, spring etc)

Could this be letting pressure by and not regulating things properly?

One other thing I checked was the in line fuel filter just before the pump. It's pretty dirty and full of crap, and needs to be replaced, but i doubt thats causing my fuel pressure to be 30 psi low...

I uploaded pics with this...lets hope they show...

 

[DaveBen]

That could be your problem. A broken o-ring is not sealing. I am not an expert on the 7.3 engines. Someone like Big Joe or someone else will join in with their opinion.

Dave

 

[BIG JOE]

there is some sort of black o-ring type fitting that goes around the brass sleeve that then sits inside of that little ring, that then sits inside the fuel bowl housing. (Mouthfull, but make sense?) That little o-ring was ripped/degraded. Everything else looked fine (main o-ring, spring etc)

Could this be letting pressure by and not regulating things properly?

*Yes

One other thing I checked was the in line fuel filter just before the pump. It's pretty dirty and full of crap, and needs to be replaced, but i doubt thats causing my fuel pressure to be 30 psi low...

*And.. it being dirty, doesn't help

I uploaded pics with this...lets hope they show...

You've found the gremlin JR.

Yer loosing yer fuel pressure because of that O ring.

The spring controls the movement of the brass sleeve. the O ring seals the sleeve. With the O ring shot.. fuel (pressure) is bleeding off, as you suspect.

The dirty filter isn't helping anything either.

Replace both and I think your problem is fixed & over.

Ford sells an FPR rebuild kit, with all the O rings (?)

Joe

On edit ? With the pressure bleeding off into the return line, @ 30+ psi.. you probably had a purdy good flow going into the fuel tank. That.. probably stirred up the crap (normal sediments) in the tank.. which then got sucked up and got trapped in the pre-pump filter.. Whalla.. the dirty filter you found. Whadya think ?

 

[dpantazis]

but consider there is an operating range for fuel pressure, and knowing that it runs means that there is enough fuel being fed to the motor.

i do not recall what the range is.

makes sense that the pressure drops at load.

are we still chasing excessive oil consumption?

you got a manual JR?

dp

 

[JRJ04]

but consider there is an operating range for fuel pressure, and knowing that it runs means that there is enough fuel being fed to the motor.

i do not recall what the range is.

makes sense that the pressure drops at load.

are we still chasing excessive oil consumption?

you got a manual JR?

dp

Well it looks like I've got some work to do!

Yea, I would understand it dropping under load, but a 20 psi drop???

No longer chasing the oil consumption...that seems to have gone away with the new injectors. What I'm still chasing is the hiccup and unburt fuel/oily residue on the back bumper.

I've got a theory here...tell me if I'm crazy...

The vibration that I've been feeling at or above 2500 rpm's...could be the engine running out fuel and shaking?

 

[DaveBen]

Injector going south would be my guess for the shaking. Or fuel pressure not up to par, as you guessed. Fix what you know is wrong and then see where you are.

Dave