need fuel flow diagram for t444e

Bungeekord · 09-15-2008, 12:05 PM

hey folks,
about to convert my bus and need some sort of diagram to explain the stock diesel fuel flow path. I can see the fuel line coming into the engine compartment, then to the filter, then to some big cylinder thing then I loose it. I cant even really tell where the IP is... Need to figure out where to plumb in the veggie line and solenoids. Does anyone have the manuals for these engines? could you scan and post that info?
thanks so much!
-ben

paul iossi · 09-17-2008, 08:12 AM

I don't have any diagrams of your fuel system, but it doesn't have an injection pump, it has a HEUI fuel system hydraulic electronic unit injectors, they use engine oil pressure to intensify the fuel pressure and then electronically fire the injectors, all controlled by a computer/engine control unit, its all electronic just like the modern automobile, that being said I think if I was going to try to use wvo, plumb it in at the fuel rail where it goes into the eengine and run the return line back to your wvo tank so your diesel tank stays all diesel

Hex · 09-17-2008, 10:24 AM

Seeing as how I'll be interested in the same info (when my bus gets in on Friday - fingers crossed), is the HEUI likely to have enough power to pull the WVO without issue, or is it likely to need an extra pump to 'help things along' through the filter(s)?

paul iossi · 09-17-2008, 06:16 PM

it depends on the tank location and consistency of the wvo, it probably would be a good idea to install a pump close to the tank to push the wvo thru the final filter and lift pump(mechanical pump on the engine)

Bungeekord · 09-18-2008, 06:19 AM

this fuel rail, where is it? u mean the metal injector lines? what does that HEUI look like? thanks

paul iossi · 09-18-2008, 08:32 AM

oops, my bad

the HEUI's are inside the engine, under the valve covers, the fuel rail is an internal integral part of the cylinder head,the fuel line you are looking for will be going to a fitting where the line goes from the chassis to the engine. just follow the lines from the tank to the engine and splice in at the appropriate fitting, also you will want to run your return lines in the same area.

Bungeekord · 09-22-2008, 10:21 AM

ok, thanks but thats still a little vague.im kind of looking for more specific details of where to splice into the fuel path with the veggie oil.
It looks like the fuel goes from the fuel filter up through a small glass bulb thing (filter?) then into a large black cylinder, then its gets messy, lots of steel lines going different places...I want to minimize heat loss by placing the fuel selecting solenoid as close to the HEUI as possible, but the engine layout makes it quite hard to follow the fuel path. If anyone can provide specifics about the t444e it would be very appreciated.
Im going to try to document this whole process and post it here when its all done, so hopefully others can utilize the info. thanks.
-ben

Verbalist · 09-30-2008, 03:14 AM

Dear BungeeKord,

I also have a T444e, and am converting it over. I am not a diesel mechanic, but I got some general books, one with a chapter on the T444e, and have been learning about it. The HEUI, is a fuel system which uses special expensive fuel injector, that basically has a built in pump. It is powered by high pressure engine oil. the fuel is delivered to the injector with a typical low pressure, about 40 psi, pump. The injector bumps it up to about 3000 psi.

I have been trying to figure mine out under the hood and it looks like there are two fuel filters. The first one is low down and looks like a typical oil filter canister. the second one is on top of the engine. You open it up, and there is a changeable filter inside. I believe that the fuel pump is attached to the engine and powered by some cam shaft. I cannot remember but I think the pump may be inbetween the two filters. This would mean that the pump sucks the fuel through the first filter and pushes it through the second.

I am planning to tie the veggie oil line in to the diesel line just before it reaches the first filter. these filters also have water separation. I think this is the best, because then you would have extra filtering action, just in case some gunk was still in your veggie oil. Of course you have to put a heater or two in the line some where. I may put a flat plate exchanger, just before the solenoid selector and the first standard filter. Then I may wrap or insulate the fuel supply lines between the filters and the pump. You could probably put an inline heater, which would heat up both veggie and diesel, and I don't think it would hurt the diesel any at all, but in my climate, it probably won't be necessary. Best of luck folks, I will keep you posted.

MMS.

Hex · 09-30-2008, 08:14 AM

Verbalist -

I'm planning on using the 'tricore' system, with engine coolent in the center of the line to maintain temp. I'm also planning on using a 'helper' pump, so thanks muchly about the 40psi figure. I'm guessing if I stay nicely below that for an inline WVO pump, I'll be in good shape.

Of course, I've got to get the bus painted and the seats out first, but the conversion process is on my list ...

Thanks!

Bungeekord · 09-30-2008, 08:46 PM

Hello verbalist,
thanks for the input. im not really into the idea of sharing the stock diesel filter for both veggie and diesel for numerous reasons. Mostly it seems you would want to keep the systems seperate so that if you experience any problems with the veg system (filters clogging, air leaks, etc.) you can still run on the stock diesel set up and drive your bus. Secondly, when you went to purge your engine of veggie oil before turning off the bus this process would take much longer if you had to flush the vegi oil out of what you are saying is 2 diesel filters. Injecting even small amounts of unheated veggie oil, especially during a cold start up, can cause considerable wear on internal engine components and is only avoided by full engine purges and assuring no vegi oil goes into your diesel tank.
In your opinion do you think that the diesel return line (which is notably a hard plastic line) is under high pressure? and what about the main diesel line. Is there any assistance pump that runs at the diesel tank that should be turned off when switching over to veggie oil?
Just a few things to consider, would love your take on all this. Thanks again for the post!
-ben

paul iossi · 10-01-2008, 12:01 AM

it would probably be benificial to order/buy the factory repair manuals for both the chassis and engine so that you know what systems are there and how they are supposed to work
use after market filters/water seperators,RACOR or GOLDENROD are popular brands, for your wvo system, they have removeable transparent bowls with drains that makes checking and serviceing them easy,
Install an electric pump at the tank to push your grease thru the system, it can also be used to bleed/purge air from the lines and filters.
don't forget to run a seperate return line (low pressure) for the wvo to keep from contaminating your diesel tank, it is necessary to circulate fuel thru the system to cool and lubricate the injectors.
try to find a fuel tank switching solenoid/valve that has provisions for both supply and return, NO scratch that you want to switch fuel in and then have time to flush the wvo out of the system before you switch return lines, seperate valves.

good luck and keep us posted

Bungeekord · 10-01-2008, 10:03 AM

i would love to buy a manual for the engine. any ideas where to find such a thing. Ive been looking for a few weeks now, on and off.

paul iossi · 10-01-2008, 10:35 AM

try your local IH Navistar dealer or google

You may also like: