Has anyone any tips on how to prime and bleed air from the diesel fuel supply on my 3b bj42? After a necessary head off job I am having great difficulty in bleeding all the air from the fuel system. I have rigged up a small tank and fed the fuel directly into the fuel pump and successfully bled the air at the fuel filter. She starts and runs fine. Syphoning fuel , ( gulp ), by mouth, from the tank and connecting it to the fuel pump also allowed it to start and run. However, next day, it wouldn't start. Going through the same procedure again gave the same successful result. Once again , next day, no joy. With my small header tank sited above the level of the injectors I notice a small leakage of fuel around each injector. Could this be where air is entering overnight? And if so am I missing some washers on the injectors ( I only used copper washers ). Has anyone tried installing an electric fuel pump after the sedimentor? Any tips anyone?
3b diesel priming problem (3 Viewers)
- Thread starter Past it
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
Posting in the diesel section might help.
However, you should have no leakage around the injectors. That is definitely not right. Also, the stock hand primer is known to fail and can allow air into the system. The Bosch replacement (I can't remember the part number, but it's posted in several places in the diesel section of Mud) is a great upgrade.
When I had to bleed mine, I would prime it with the hand primer and crack each injector line until I started seeing fuel. Tighten down the fitting and try starting it up. Once running, I would again crack each injector line and let the air bleed out. Once the idle smooths out, you know you have the air out of the lines.
Good luck!
However, you should have no leakage around the injectors. That is definitely not right. Also, the stock hand primer is known to fail and can allow air into the system. The Bosch replacement (I can't remember the part number, but it's posted in several places in the diesel section of Mud) is a great upgrade.
When I had to bleed mine, I would prime it with the hand primer and crack each injector line until I started seeing fuel. Tighten down the fitting and try starting it up. Once running, I would again crack each injector line and let the air bleed out. Once the idle smooths out, you know you have the air out of the lines.
Good luck!
- Joined
- May 21, 2009
- Threads
- 296
- Messages
- 1,382
- Location
- Paradise Calgary Alberta Canada
- Website
- forum.ih8mud.com
Change your fuel filter, crank your injectors down to the right foot pounds this is critical for milage !
* Being out just one pound can lead to sh*t milage.
use the bleed screw with a hose into a pop bottle so you can watch the fuel go from air and fuel to straight fuel by pumping the primer pump !
If you have fuel escaping from the primer pump you will need a replacement pump, Bosch has one.
Check for any fuel leakage along the fuel lines around the motor back to the tank.
Adding a fuel pump will do nothing as your diesel won't run with any small amount of air in the system.
* Being out just one pound can lead to sh*t milage.
use the bleed screw with a hose into a pop bottle so you can watch the fuel go from air and fuel to straight fuel by pumping the primer pump !
If you have fuel escaping from the primer pump you will need a replacement pump, Bosch has one.
Check for any fuel leakage along the fuel lines around the motor back to the tank.
Adding a fuel pump will do nothing as your diesel won't run with any small amount of air in the system.
Thread revival. Does anyone have the secret to get fuel up to the injectors? I opened the bleed on the pump hsg and pumped the primer until it sprayed out. The hand pump leaked like crazy but I screwed it back in and closed the bleeder. The pump should be air free. I cracked the lines at the injectors and had my son crank the truck. No diesel comes out at all. Fuel is not reaching the top of engine. We cranked for about 10 to 15 seconds a number of times. Lines to the injectors are completely empty. What am I missing?
P.S. Has new fuel filter. There is no bleeder on the filter hsg. Just the one on the side of the pump.
P.S. Has new fuel filter. There is no bleeder on the filter hsg. Just the one on the side of the pump.
There is a diesel forum around here some where. So did you fill the new fitler - that a big air space? Maybe your weak primer pump only pulled some fuel out of the line between filter and pump. I would fix your primer pump. Any way crack one bleeder on the injector and use primer pump until you get fuel - move to next injector.
Are you sure the fuel system is "on" - NO CLUE what you have for controls - My 2.5 ton hand a simple cable to turn off the fuel so the engine would quit. Release the handle and the system was ready to run again.
Leaking pumps let fuel out and air in - not what you want in a system that doesn't deal with air well.
Maybe you could pull some vacuum on the lines at the injector and such fuel up to them, then reattach as each line fills.
Are you sure the fuel system is "on" - NO CLUE what you have for controls - My 2.5 ton hand a simple cable to turn off the fuel so the engine would quit. Release the handle and the system was ready to run again.
Leaking pumps let fuel out and air in - not what you want in a system that doesn't deal with air well.
Maybe you could pull some vacuum on the lines at the injector and such fuel up to them, then reattach as each line fills.
Fit a new primer pump - try a John Deere dealer, get one for an old 40 series tractor, 4240, 4440 something like that. They used a Bosch inline pump and our Densos are Bosch under licence - they're not expensive but take yours along to check. Crack the outlet pipe on the filter housing and pump until no more air bubbles in fuel OR fit a housing with bleed nipple. Then move on to pump bleeds, finally crack 1 injector union at pump before trying starter motor, tighten this when the other 3 run ok.
Thanks for the response. I too have the choke cable hack to the fuel shut-off.
I assume if the fuel is getting to the pump that the filter upstream is full. It took several pumps initially to get any suction. Now it fires out the bleed screw like a rocket.
I was gonna hook up a Mity-Vac brake bleeding tool to an injector line and suck the fuel up. Is that what you are suggesting as well?
Thanks for the response. I checked multiple years and models of Landys with 3Bs. 22501-77021 is the part number on all of them. I assume I need the gasket spring and valve as well. Gasket at least?
I love my might-vac but the crappy job they do making wheel cylinders these days it almost easier to do the two man brake bleeding procedure.
Yes I would give it a try -
Maybe there is manual here free downloads Land Cruiser Factory Service Manuals (FSMs) - https://www.cruisercult.com/factory-service-manuals
Yes I would give it a try -
Maybe there is manual here free downloads Land Cruiser Factory Service Manuals (FSMs) - https://www.cruisercult.com/factory-service-manuals
Spring and valve normally just stay in the body, I think the gasket is just an o-ring, all you need is the primer bit that ends up leaking like a sieve. On John Deeres too. Not intimate with how a 3b return system works, I've worked on Bs, 2bs and currently a 13b, theres a steel line connecting all 4 injectors, does this return to the gas tank or back to the filter housing? If yours goes back to the filter this can make priming a longer exercise. If it goes to the tank the Bs, or anything with the inline Bosch normally prime really easy. Don't think you'll be able to suck thru an injector line but don't mind if you prove me wrong.
Last edited:
The return goes to the front of the pump. I pulled 30 inHg of vacuum (the max the MityVac will go) on 2 lines. Let it sit for several minutes. Not a drop of fuel came up.
I took the bleed screw completely off the pump and drained fuel out to start from scratch. I pumped it about 6 or 7 times and despite the flood of gas from the plunger, I could feel the resistance building. Opened up the bleed and fuel sprayed out. So I assume the plunger is working. But the resistance was minimal. Don't know if it should be relatively hard to push in once the pump is fully primed (My first diesel and don't have a feel for it
). Is the handpump supposed to push fuel all the way up to the injectors? In which case I will order a new one.Have never tried hand pumping to injector, don't think it will. When the return goes back to the pump air recycles round in the system and priming takes longer tho you still get there - back to tank is much better. Sounds like your primer is working, solid gas out of the pump bleeds is all you need. The indirect injection Bs need a lot of heat to cold start - are your glow plugs working? I'm running a 13b which solves all that. Crack 1 injector line, get a heavy jump lead and take power directly from your battery to the shunt that hooks all the glow plugs together, give it 10 seconds and try starting. If it starts chuffing white smoke its getting there. Is your BJ 12volt or 24? The amount of fuel you see at an injector is tiny, enough for 1 combustion stroke every 2 turns of your engine.
Last edited:
I had cracked the injectors and had son crank the engine the other day. No fuel came out. No glowing - I just wanted to bleed the system. To me the pump is primed now. Do I crank it like crazy and let the pump do its job? I don't wanna burn out the starter.
Have you found a manual for it yet. You need to follow a proper procedure to bleed/prime the system if you don't want to waste time and money. I'm not really a diesel guy but you should find that section and ask for help there.
Yes, if pump is primed it doesn't take long. Don't do more than 10 seconds heat first tho others say up to 20 seconds - I would give it a serious chance at starting, a B won't cold start without heat. Don't play with ether, either. I ran a B and then a 2b powered irrigation pump for over 30,000 hours combined - made most of the fuelling mistakes you can make. If your glow system is all good you could always try tow starting, put it in 3rd and drop the clutch. No starter motor issues.
Last edited:
I've ordered a new handpump. Youtube videos show guys pumping and no fluid leaks. So I'd rather have a new unit to at least eliminate one suspect component. I'll try to start it again this w/e. (Busy tomorrow). I've been following the manual to bleed it so hopefully if I glow for a while she'll catch. Otherwise I'll wait for the new pump and start the process again from the beginning. Thanks alot for the help so far guys.
