M35A2 fuel to injectors diagnostic issue

[JDToumanian]

Make sure it's actually coming out the vent tube.... The turbo drain line is close by, maybe that's leaking and oil from it is pouring down the side of the vent tube. That much oil out the vent tube wouldn't be good.

 

[Gleeser]

There's no turbo. It's comin out the vent tube. I'll report back this afternoon on it.

 

[Gleeser]

I went ahead and changed the oil. I drained roughly 12 or 13 gallons of diesel/oil out of it. I'm looking at bypassing the FDC and hoping that fixes this issue.

 

[Gleeser]

Alright, I bypassed the FDC after changing the oil. I had put 12 gallons of fuel in the other night before all this. I got the truck fired back up awhile ago and let it idle looking for leaks. It idled roughly 5 minutes and then it's sucked the tank dry.

My question now is this: If the FDC was causing my fuel in oil issue, is it possible that I pumped 10 gallons or so into the crankcase before I bypassed it?

Keep in mind that I drove it maybe 500 yards or so just above idle before I bypassed the FDC. I guess I'm wondering how much fuel can flow into the crankcase if the FDC is problematic. Is it capable of just dumping fuel into the crankcase or is it only likely that it will trickle in there over time?

If it's capable of just dumping fuel in there then I will feel safe refueling the truck and running it awhile. If it's only possible that it will trickle in then I'd say I have a major malfunction elsewhere.

The other thing is, do I need to adjust my fuel delivery down because of this bypass? At the moment I'm making almost no black smoke anywhere in the rpm range. I have a little blue smoke above 1500 but that's about it.

 

[doghead]

I guess I'm wondering how much fuel can flow into the crankcase if the FDC is problematic.

The in-tank pump can pump around 3 gpm.

You need to pull the boost pump and see if that is leaking around it's shaft.

Just pull it out and let the in-tank pump run.


Also, you did reinstall the 2 O-rings on the hydraulic head, right?

 

[Gleeser]

There's 2? I only saw the one large one around the base of the HH Also, not sure what you're referring to as a boost pump. Sorry, really new to this multi-fuel stuff.

 

[doghead]

The boost pump is on the side of the injector pump. It has fuel lines connected to it(obviously).

 

[m-35tom]

if the small, bottom (2") o ring is missing from the HH you should see fuel comming out where the shutoff cover goes. (remove the cover, it does not have to be there for it to run)

 

[gimpyrobb]

O crap, I forgot to ask about the HH o-rings. Yes there is 2 of them. One is 2.484x.139 the other is 2.109x.139.

 

[JDToumanian]

One is 2.484x.139 the other is 2.109x.139

Now that's some useful information right there! That should be in the parts cross reference section or something....

 

[Gleeser]

This morning I went and got another 12 gallon and dumped in the tank. Started the truck, let it idle, watched the fuel level in the tank. It was quickly diminishing fuel so I figure it's still dumping fuel into the crankcase.

First thing I did was pull the cover off the engine shut off. I started the truck back up and it's raining fuel out of there at a pretty good clip. From what m35-tom said the lower o-ring is either busted or missing from the HH. I guess I'm gonna pull that again and check it out. I plan on doing that after lunch... as long as I can find those o-rings somewhere.

I hope that's the problem but at this point I won't be surprised if every single thing that could put fuel in the crankcase is bad.

 

[Gleeser]

Yeah, went back after lunch, picked up the old HH and guess what was wrapped around it? The 2nd o-ring!! geez... Anyway, I took it all apart put 2 new o-rings in there and drained the case again. I drained 14 gallons out this time. replaced the oil and lit it back up. I watched the fuel in the tank again and this time it did not appear to go down like last time. I think I may have it remedied now.

Thanks for all the help to this point. You guys are really generous.

Grant

 

[doghead]

You do know you can use all that oil and fuel in the fuel tank, right?

 

[Gleeser]

Yes sir.

 

[gimpyrobb]

I am sorry I over looked the O-ring issue. I should have known better. Sounds like today was much more productive for you!

 

[Gleeser]

Nah dude, not your fault. I should have been paying attention. Took me less than an hour to fix it. Wasn't any big deal. Yeah today was productive for sure. My neighbor just informed me via txt that he has 4 new 46" tires he wants to get rid of. Trying to get ahold of him to find out more info, that's all I know other than they are for 20" rims.

My questions will start leaning towards bobbing this pig shortly. Mainly parts questions. I may not be a master mechanic but I'm a killer fabricator and I am dying to start cutting this thing up. Trading the rear axle for the use of a heated shop this winter. Dang 8 foot tall door on my shop isn't going to allow any deuces inside it.

 

[gimpyrobb]

If I can help at all, gimme a call.

 

[digitaldust]

can someone post photos of there HH fix or swap, I think I'm down to that.

thanks

 

[kennys@wi.rr.com]

can someone post photos of there HH fix or swap, I think I'm down to that.

thanks

If you click on the HH rebuild link in my sig line it will take you to my thread about it.

 

[nwolfe93]

help please

ok i am experiencing the same issue. everything was running and working fine and then i just quit getting fuel to the engine. i am sorry that you had the problem before i did but hopefully you can help since you have dealt with it. i assumed i should start at the injection pump but after reading all of this that doesnt seem to be the problem. where should i start to avoid any added confusion, stress and money than neccessary. your advice would be greatly appreciated as this is my first duece and a half. hope i get a response soon so i can get this bad boy rollin