H engine fuel delivery issues

[drdalloway]

Happy New Year Cruiser Community!

I'm in need of some fuel delivery advise on my H engine, so I'll try to set up the scenario as quickly as possible:

First, the truck is a bit of a Frankenstein monster--a 4 speed Costa Rican BJ40 with an H engine that has clearly been pieced together on no known Land Cruiser paradigms. I've put in a Wilson switch for the glow plugs, and it works., but I anticipate having to re-wire the whole truck at some point this winter. Suffice it to say that I was misled about the state of the truck when I purchased it; had I known then what I know now, I would not have taken delivery of the vehicle. But I did and now I'm trying to fix some issues as economically as possible, using limited abilities and knowledge (four previous cruisers--73 FJ40, 77 FJ40, 84 BJ60, 90 FJ62)

When the truck was delivered to me, there was no fuel in the tank or the line. I did the standard things--checked the lines, replaced some of the rubber hoses, filled the tank and used the primer pump to get fuel in the line to the filter, etc. Then I changed the filter, filled it with fuel and bled the line until the fuel flowed freely from the bleeder nipple. Then I bled the injection pump and got fuel to all of the injectors by cracking the nuts, hitting the starter for each line until the fuel pimped out with no air. The truck started, but then after approximately two minutes (the time it took the fuel from the filter to burn) the engine sputtered and quit.

Because it appeared that the fuel delivery problem was from the primer pump back (it pushed the fuel from the filter to the injector pump, but did not seem to draw fuel from the tank) I replaced the primer pump with another Bosch unit, replaced the plastic washers on the lines with copper ones, and repeated the process with the same results. So, as far as I can ascertain, the injection pump is pulling fuel from the primary filter (there is no sedimenter in this particular set up, though I would like to install an after market unit), but no fuel is being pulled through the line from the tank. Nevertheless, when I loosen the metal line from the tank on either end--engine side or tank side--fuel flows out, but it appears that primer pump does not efficiently pull fuel from the tank.

Further, when the truck runs for the two minutes it takes to run out of fuel from the filter, it smokes like a mofo. I would think that might be the mark of problematic injectors, injection pump, or just excess carbon buildup, but I can't get it to run long enough to see if it clears up to get a better idea.

So, a couple of questions:
1) Could this be the result of a tired injection pump? (I don't know how many miles it has on it) or fouled injectors?
2) Could the lack of suction in the primer pump be indicative of an air leak somewhere in the fuel line from the primer pump back?

I think my next move is to replace the metal fuel line in case there are any tiny holes in it (there is no apparent fuel leak, but I know that does not preclude air entering the line through holes too small for fuel to leak from).

Any advice would be appreciated. And for the record the conversations on this site are incredibly instructive, even when they are not terribly serious. It's cool to see a group of folks out here as enamored with these truck as I am.

Thanks Ya'll!

 

[duncanrm]

A few things:

• It may in fact be sucking air - ie it may be drawing from the tank fine
• You speak of replacing the Primer Pump but you may or may not know that there is in fact a "Lift Pump" this is what the primer pump screws onto and it's also a candidate for having failed if you're in fact not drawing air. Its easy to remove for inspection
• You mentioned replacing the crush washers.. did you end up with one each side of each banjo and are they good and tight with no sign of weeping?
• I would give the inlet to the lift pump a clean source of diesel with a hose directly from a small can and see if manages to run for longer
• If it still doesnt run on a clean source of diesel direct to the lift pump I would give it a clean source of fuel supplied with a small 12V fuel pump to see if that assists - if it does, I'd look more closely at the lift pump (here's a video I made of one that failed.. its from a 2H but the H one is identical : Lift Pump Video

 

[ceylonfj40nut]

I have a whole slew of H engine parts that came off a rig I bought. Pls let me know if you need anything.

 

[roscoFJ73]

but did not seem to draw fuel from the tank

The hand pump should pull fuel through in 25-30 pumps, if not you have problem.
I agree with duncanrm's suggestions but I would also be checking the fuel pick up in the tank. Often a blocjakge will allow small amounts of fuel to flow but not enough to keep it running.
I would also set up another fuel supply in the engine bay.

What colour smoke does it make when it runs?

 

[ozcrusier]

Also if the engine has low oil pressure the edit will shut the engine down.

 

[drdalloway]

Sound advice gents. The engine has good oil pressure; even if it didn't, the sending unit for the shut off is not connected--like I said, this unit is a Frankenstein monster. I'll start of the electrical re-wire once I get the fuel issues resolved.

The crush washers are solid with no weeping. Roscoe, the smoke is white and there's a ton of it; I'm assuming that means diesel and not oil. Probably a good thing. It does not start drawing fuel with 25-30 pumps, and I have changed out the primer pump. Too, fuel gushes out of the tank line (pre metal line) when it's unhooked. I set up an aux fuel tank in the engine bay and had the same problem, so I don't think it's the pre-lift pump supply.

Regardless, I'm going to replace the metal line with a new one, I think, and I am going to take Duncanrm's advice on the lift pump, because all indicators point there as the culprit. Thanks for the video, by the way--that helps with process. I'll report back once I have done all these things.

Do the H and the 3B use interchangable lift pumps? If they did, sourcing would be easier for sure.

Ceylon, I might be hitting you up for some engine parts if the need arises.

Thanks again!

 

[code 621]

Tons of white smoke sounds like the diaphragm w/ a hole in it.

 

[roscoFJ73]

Roscoe, the smoke is white and there's a ton of it; I'm assuming that means diesel and not oil.

White smoke is condensation from combustion that is not hot enough. It can be bad timing. Or it could be weak springs in the injectors allowing the injector to open too early which is similar to a timing problem.
Normally the fuel combusts as it comes out of the injector, like a dragon breathing fire, but in this case it begins to combust as the piston is still traveling upwards.

 

[crave reFleXion]

I agree with Rosco and would look at IP timing. You could also plumb in a new fuel line to a tank of diesel to take the fuel lines and tank out of the equation.