Major injector leak issue

[WrickM]

ok here's my deal. In order to save money on fuel, and because it seemed like fun I installed a (greasecar) Waste Vegetable Oil burning kit on my 1987 F250 6.9. Now two weeks after than install almost every single one of my injectors is leaking, and not a little. It's like a stream of fuel running off of the engine. My initial though was that a couple of tanks of B20 biodiesel had somehow destroy the o-rings. I didn't think that was supposed to happen but why else would all the o-rings fail at once? After doin some research on this very fine and informative forum i have begun to suspect another culprit. The fuel seem to be coming from under the black cap on the top on the injector. when istalling the greasecar kit i was told to block off the braided fuel line where it attaches to the fuel filter outlet with some jb weld to insure the wvo an diesel didn't mix. Now i feel like i have blocked off the injector return lines and it is over pressurizing and overcoming the o-rings. Does that seem plausable to you folks.

any ideas of what i can do now short of the obvious trying to gring out the JB weld?

I appreciate any input thanks

 

[Dsl_Dog_Treat]

Why on earth would they tell you to block a return fuel line so 2 compatible fuels can't mix????:***:

You are correct that the excess fuel is pushing past the caps on the return lines and I suspect that you will be purchasing a return line kit and replacing those in the very near future.

The pumps supply more fuel than the motor uses most of the time and it's gotta go somewhere, so the way these systems are designed, they return the unused heated fuel back into the filter head assembly to be reused first before fuel from the supply tank is drawn, heated and filtered. The excess is gonna have to go somewhere.


I'm not familiar with the kit in question, but if it has a separate tank for the fuel, I think what they are trying to get at is to reroute the excess fuel back to that tank instead of pushing it into the stock tank which would eventually overfill. In that case, there's a return fuel line at the back of the motor that does return any excess fuel to the stock tank. That line would need to be capped then and not at the filter head.

 

[WrickM]

ok did some more research and they told me to block the braided fuel line that is more or less the injection pump bypass. The injector return (braided) line does meet with the return line at the last injector on the drivers side. So thankfully the greasecar kit and the plug line are NOT the issue. i experimented some and the issue does not occur when the return solenoind is working in WVO mode so i think there is a clog either in the diesel return line or in the diesel side of the return solenoid. I will be testing both this evening to resolve this messy issue.

 

[WrickM]

Why on earth would they tell you to block a return fuel line so 2 compatible fuels can't mix????:***:

I think they segregate the fuels to prevent the unheated WVO from building up in the diesel tank and clogging it. It also prevents the wvo from overflowing the diesel tank and vice versa

 

[Dsl_Dog_Treat]

ok did some more research and they told me to block the braided fuel line that is more or less the injection pump bypass. The injector return (braided) line does meet with the return line at the last injector on the drivers side. So thankfully the greasecar kit and the plug line are NOT the issue. i experimented some and the issue does not occur when the return solenoind is working in WVO mode so i think there is a clog either in the diesel return line or in the diesel side of the return solenoid. I will be testing both this evening to resolve this messy issue.

That will be the line going back to the tank.

So it works in WVO mode but when you switch back to the stock fuel system setting it is forcing the fuel out the injector return line caps?
Sounds more like a misrouted return line.

Got pics of the setup and how ya have it plumbed in?

First time veggie in a system will clean everything out as to not rule out a plugged line tho.

 

[icanfixall]

These fuel systems that are the stock systems work great plus... They act as a cooling agent for the injectors and the injection pump. The fuel that is not used returns to the tanks from the injection pump and the injectors on the same line. This system is required for proper operation.

 

[mcbg]

ok did some more research and they told me to block the braided fuel line that is more or less the injection pump bypass. The injector return (braided) line does meet with the return line at the last injector on the drivers side. So thankfully the greasecar kit and the plug line are NOT the issue. i experimented some and the issue does not occur when the return solenoind is working in WVO mode so i think there is a clog either in the diesel return line or in the diesel side of the return solenoid. I will be testing both this evening to resolve this messy issue.

Get the injector return kit, its easy to install( check the cond. of the inj. while your at it- I wish I would have when I tried a new fuel)

http://www.oilburners.net/forums/showthread.php?t=30933

check that you solinoids are working correctly( are the the black pollack valve- because these fail)

 

[Mat J]

someone correct me if im wrong but doesnt he need to switch all the regular rubber lines and orings and whatnot out to vition or neoprean also.

 

[DeepRoots]

no mat j you do not.
I didn't ever and I ran alot of wvo and biodiesel.

Wrick M, you need to really sit down and figure out how your fuel system works.
You seem like you don't have a basic understanding of the 7.3 fuel routing. sure, you can do whatcha want, but I fear that you will end up spending more on IP's and injectors than what you save on wvo.

Biodiesel is a safe fuel if used properly.
Best of luck
Drew

 

[NextENRG]

no mat j you do not.
I didn't ever and I ran alot of wvo and biodiesel.

i used to produce biodiesel commercially. yes WVO will have the same effect on organic rubbers ect... as biodiesel will, just not as quickly.

what you should be worried about it FFA content, sugars and protiens, and bonded water

 

[WrickM]

o.k. checked to make sure the valve was installed and routed properly. It is. Used compressed air to verify that valve flows from common return to diesel return line with no power applied to the solenoid. It does. Checked the return line with compressed air and it seems only to blow back into the rear tank. Alos pressure builds pretty quickly with the gas cap on as though maybe it isn't venting well. Loosened the cap so air can flow around it thinking that might solve the problem. No luck. When the solenoid is returning to the diesel tank the injectors all leak. . . badly. My only thought is that maybe there is a clog in the small return line that connects all the injectors. I don't know how to really check that just yet, but i would think if that were the issue then the WVO would leak out of the injectors too.

I have reviewed how the fuel system works. i purchased a manual for the engine. i see where the fuel should be going i just can't figure out why it isn't getting there. The solenoid flows. . the lines flow and yet is acts like it is blocked.

 

[icanfixall]

The fuel tank change over valve may be bad. Its under the truck on the drivers side frame rail near the end of the front tank. Find it and remove the return line from it. Try to blow air thru the line again. If it works the problem is the valve. Fix it or replace it. The valve has a electrc motor in it that opens and closes to the front and rear tank.

 

[Dsl_Dog_Treat]

If you feel it is plumbed correctly, it may be that the truck has the older or original return lines and orings on the injectors and the wvo may be eating them up. Never seen it happen so quickly tho.
I've been running a 75 % mix now for a couple of years without problem other than fuel filter swaps.
Sumpthin still aint right.

 

[WrickM]

I have narrowed the pblem down to the trucks metal return lines. Maybe the switch over valve that was previously mentioned. I used a fuel can to catch the return fuel coming out of the line and it flowed nicely and the injectors iddn't leak. I can blow into the remaining return lines with some difficulty, but not too much. I can hear bubbles in the tank. hell i can blow the fuel out of the tank with a compressor, but as soon as i hook the return lines up the injectors begin leaking. . . i may have to take it to a mechanic to get the valve swapped. i looked at it and its seems pretty tight to pull that out. . .i am not sure what else it could be. i will try replacing the injector o-rings first, bucause it can't hurt. .

 

[WrickM]

ok i am going to try replacing the injector return lines and injector o-rings, because i don't know what else to try. For the life of me i can't figure out why it is only leaking with diesel and not WVO. The valves are right and tested. The lines are clear. I can blow air into the tanks along the return line. . . . .baffles me.