PSD fuel filter questions - Diesel Forum

ToddT · 11-19-2005, 05:25 PM

In tracing the fuel lines in and out of the stock '02 PSD fuel filter housing, I can see it:
Fuel supply- driver's side of the housing, down low
Fuel return to the tank- same side up high
Fuel to engine- two lines down low, passenger side.

I can see how these fuel lines go to the front of the driver's side head and the rear of the passenger side's head.

Is the fuel pressure regulator inside the small housing where the fuel exits the stock fuel filter housing?

Are those heating elements down in the bottom of the housing, below the level of the filter? If so, when are they activated?

My goal is to add a different fuel filter to the system and have a blank to fill the space of the stock filter element. This will reduce the fuel volume in the system when I change between diesel and WVO and more importantly... back to diesel.

What is inside the housing immediately to the front of the round filter housing. This is probably 2" thick, 10" or so wide and 8" or so tall, unpainted aluminum. Larger hoses come from the center of the heads to this.

Thanks,

Todd

flyingisbest · 11-19-2005, 09:08 PM

Here's my 2 cents. I wouldn't mess with it. Put an entirely separate fuel system in. Look at installing the Vegistroke style setup. That way if anything goes wrong (and it will) the diesel setup will just take over. You will need a couple inline check valves, I used Parker-Hannefin units with compression ends, installed in each of those 2 steel fuel lines that go to the head. Then use the other 2 ports to do similar fuel entry into the heads, but wiht heated, filtered veggie from your completely separate source. There is NOTHING better in doing these conversions than having the utmost confidence that if ANYTHING goes wrong with the veggie circuit, the diesel one will take over without doing anything. Of course if you kill injectors therein lies the exception. the stock fuel pumps aren't so great pumping veggie. They are expensive to replace. Hope this helps.

I removed my entire, newly installed system today. It worked flawlessly. Only problem is that a Ford TSB for "exhaust smell in cab" got me. It stinks so bad in the cab cause of leaky manifolds I was getting nauseous. And despite trusting my dealer to overlook my install, I didn't want to take a chance on a Ford warranty goon stopping by and cancelling my warrranty, blaming their design flaws on my install. Oh well, it gives me a chance to go change some things in the design to make it even better.

macinco · 11-20-2005, 03:19 PM

"What is inside the housing immediately to the front of the round filter housing. This is probably 2" thick, 10" or so wide and 8" or so tall, unpainted aluminum. Larger hoses come from the center of the heads to this. :"

Sounds like you are referring to the HPOP (high pressure oil pump)

ToddT · 11-20-2005, 04:53 PM

I was wondering about that... except the fuel lines enter the heads elsewhere. These have larger hoses that come out of the heads about mid-way. Do they have lines coming to and from the heads in these bigger hoses? And therefore, are there check-valves in the heads where the main fuel lines feed in?

Todd T

macinco · 11-20-2005, 05:15 PM

There is no fuel in these lines (from the HPOP). The square thing is actually the HPOP reservoir, and is fed by the normal oil pump on the front of the motor. The HPOP (below the res.) makes very high pressure (~2000-3000psi?). This high pressure oil is then feed to a journal/passage in each head (via those thinker lines you are seeing). (There is also a journal/passage for the fuel in each head). In any case, an injector gets it's fuel cavity filled from the fuel journal, and at the right time a solenoid opens and lets the extremely high pressure oil in and force from this high pressure oil is what plunges the injector and sprays the fuel through the injector tip.

Hope this helps, and hope I got the explanation close to correct.

ToddT · 11-20-2005, 09:03 PM

Thank you VERY much.... now it makes sense. The heads have high pressure oil and fuel. The injectors are driven by the high pressure oil.

Anybody know anything about what I suspect are heaters in the bottom of the filter housing?

Todd T

macinco · 11-20-2005, 10:25 PM

Regarding the fuel bowl heater, I would like to know also. I am pretty sure about it being a heater, but whether it is on all the time, thermostatically controlled (with sensor on the fuel bowl), computer controlled, timer (or what), I have no idea.

And the thing on the drivers side of it is a pressure regulator, I do know that. People shim the spring to increase fuel pressure.

If a person could find a place to mount it, I was thinking an extra one for a duel fuel system would be nice (because of the built in pressure regulator and the heater.) I have seen them come and go on ebay fairly cheap. But the elements are a little expensive. You can get them cheaper (~$10/ea on ebat) if you buy several.

I also get confused when I read of high performance duel systems having fuel coolers. I would think hotter (to a point) would be better, because of lower viscosity and therefore better injector spray pattern.