13bt rough idle, sometimes wont start

[roscoFJ73]

Can I get some clarification on bleeding the injectors? Some threads say to crack all four and crank the engine until gas comes out all of them. Other threads say run the engine with one port cracked until it stops foaming. Are both methods safe/valid? I read horror stories of injector heads doing awful things to the cylinder internals when they don't spray right..

Either way is ok. If the engine is capable of being started I would crack one at a time while its running. It might help to have it idling at 1000 or so.

If the engine wont start because its been reassembled or had a major airleak, then bleed all 4 first, then start it and repeat one at a time if it wont run right.
Some owners over think this , all you are doing is removing a few bubbles of air from the injector lines.

Another way is to remove all the glow plugs (if you have them) and crank it with no compression. Within 30 seconds you will see plumes of diesel exiting out of each glow plug hole, then put the plugs back in and it will start immediately.

Diesel engines are fairly tough inside , it takes a long time to destroy them through a poor spray pattern. Poor spray patterns tend to form chunks of unburnt fuel and oil on top of the piston, this glows like an ember and eventually can burn a hole in the piston. But this takes years.

 

[Nz Nath]

For what it's worth, the 13bt in this thread is plumbed identically to mine.

That's how my 13bt is plumbed as well.

 

[pradoblivious]

Things have progressed to the point where I can't bleed it anymore. Went out to re-check everything again today and bleed it after I replaced the fuel filter yesterday and it just ran for 30 min with foam coming out the injectors..



I went over the metal fuel lines inch by inch, took apart the banjo bolts to the IP/Filter housing (they look fine to me). I'm beginning to suspect the lines in my tank.

At my mechanic's advice, I'm going to grab a gas can from walmart tonight, and run a hose to it to see if I can isolate the leak.

 

[AirheadNut]

When I do the LiquiMoly diesel purge I just run some fuel line from the IP to a clean pop bottle full of fuel and run the engine off that. Works great and you can see what is happening.

 

[roscoFJ73]

At my mechanic's advice, I'm going to grab a gas can from walmart tonight, and run a hose to it to see if I can isolate the leak

Good advice, it would have been my next suggestion. Do you have that new Bosch hand primer yet?

 

[pradoblivious]

It should be here tomorrow :fingers crossed:

 

[pradoblivious]

Hey yall. I've had to travel for work for a while, but I'm back at this now and I have a couple of questions. Here's my fuel system as I currently understand it..

Here's what I've done so far

• I've replaced all four hose sections of the fuel line between the tank and the lift pump.
• I've replaced the hose-section of the common return line from the injectors to the IP
• I replaced the fuel filter
• I've removed the banjo bolts on the lift-pump and filter housing to inspect the plastic washers and make sure everything is tight
• I had a bosch hand-pump on order but that order was cancelled by the parts dealer and I haven't had a chance to order another. I don't think this is the source of my leak however, because my hand pump is a brand-new OEM part, and it's not leaking gas.

Last night I poking around and noticed some rough spots on the pump-to-filter hose, so I removed it to inspect and found that it was pretty severely cracked

I see this hose at cruiserparts.net for $125 and I will replace it asap. 3B Fuel Hose Sub-Assembly Injection pump to filter [D 23802-56040 - USED] - $125.00 : CruiserParts.net, Toyota Landcruiser Parts

Obv I'd appreciate any advice yall have for a better/cheaper source. In the mean time I've wrapped it with some loom harness tape (which hasn't seemed to help with the leak at all).

I'd been trying to isolate the leak with a soda jug full of diesel and some fuel line, but that was too fiddly, so I've picked up a proper diesel can at walmart, and I'm going to have another go at it.

Here are my questions:

Where does vacume end and pressure start in this fuel system? I've read that the lift-pump is mechanically powered by the IP (see for example roscoFJ73's post in this thread). From this, can I infer that everything AFTER the lift-pump is under pressure, and everything in front of it is under vaacume? If that's a safe assumption can I also assume that my air leak has to be between my tank and the lift pump (because otherwise I would be leaking fuel instead of sucking air wouldn't I ?)?

Second question, I've read that the 2h and some versions of the 3b don't have a return line to the tank (I do). In those versions, the air leaked into the system is recycled through the IP, back in to the injectors. Is that still true of engines like mine that have a return line, or is the air ingested by my system passed back into the tank? In other words, is bleeding the system the only way to get the air out of my system, or will it eventually work itself out into the tank once the leak is plugged?

 

[roscoFJ73]

Where does vacume end and pressure start in this fuel system? I've read that the lift-pump is mechanically powered by the IP (see for example roscoFJ73's post in this thread). From this, can I infer that everything AFTER the lift-pump is under pressure, and everything in front of it is under vaacume? If that's a safe assumption can I also assume that my air leak has to be between my tank and the lift pump (because otherwise I would be leaking fuel instead of sucking air wouldn't I ?)?

Correct. They have to be leaking bad before fuel comes out. The vacuum in the fuel line is only 1-2 negative psi from memory.
Sometimes these get rust on top of the fuel pick up at the tank and get air in there

Is that still true of engines like mine that have a return line, or is the air ingested by my system passed back into the tank? In other words, is bleeding the system the only way to get the air out of my system, or will it eventually work itself out into the tank once the leak is plugged?

I have never thought about it, but I think the air would work its way back to the tank if it isnt sent through the injectors. Once engines get to the point where there is only a minute amount of air, they seem to self bleed fairly well as long as the leaks are fixed.
I never bleed mine after changing a filter, I just turn the idle up and let it chug away and give the primer a pump if it needs it.

 

[pradoblivious]

Finally gave up and paid a local land cruiser specialist (Dadja) pressurize the fuel system in search of a leak. None was found. Earlier this week I took the truck back up to the mechanic who did the swap and left it with him.