Has anyone tried this bleeding method: spraying diesel into the air intake?

Interesting.

Need someone to try that on a boat engine, ideally someone with a Yanmar 3GM so I can see it working...
 
I've got a little Ford compact tractor that's a beggar to start if you let it run out of fuel. I'll certainly give it a try next time I forget to check the tank.
 
Presumably the engine started initially because the injection pump was still full of fuel as he had only changed the lift pump. Then the engine was kept going by the fuel being squirted into the air intake until it had bled itself.

I would like to see this done with a completely dead engine where the entire fuel system needed bleeding.

On my BMC 1.5 if it's just the lift pump or the filter that needs bleeding it would be simpler to just bleed at the filter head. Then start it up.
 
SlowlyButSurely said:
Presumably the engine started initially because the injection pump was still full of fuel as he had only changed the lift pump. Then the engine was kept going by the fuel being squirted into the air intake until it had bled itself.

I would like to see this done with a completely dead engine where the entire fuel system needed bleeding.

On my BMC 1.5 if it's just the lift pump or the filter that needs bleeding it would be simpler to just bleed at the filter head. Then start it up.
Click to expand...

The engine in the video had, allegedly, run out of fuel.

On one of my BMC 2.2s, over the last few days, I've bled: the lift- pump, the secondary filter, the injection pump, and the injectors. It still won't start.

It's an engine that's been trouble-free for years, and started easily, and ran beautifully, just last week.

Now ....... where's my bleeding spray bottle got to?
 
Isn't there a danger of pre-detonation (or whatever the equivalent is on a diesel)? Surely putting diesel in the air-intake means that it will burn as soon as the adiabatic heating of the air and diesel mixture reaches ignition temperature - which could be before the piston reaches TDC? And in that case, it's going to put stress on the crankshaft and con-rods. The point of the injector system is to ensure that diesel doesn't enter the cylinder until just after the piston reaches TDC.
 
AntarcticPilot said:
Isn't there a danger of pre-detonation (or whatever the equivalent is on a diesel)? Surely putting diesel in the air-intake means that it will burn as soon as the adiabatic heating of the air and diesel mixture reaches ignition temperature - which could be before the piston reaches TDC? And in that case, it's going to put stress on the crankshaft and con-rods. The point of the injector system is to ensure that diesel doesn't enter the cylinder until just after the piston reaches TDC.
Click to expand...

Thank you for those wise words of caution.
 
NealB said:
The engine in the video had, allegedly, run out of fuel.

On one of my BMC 2.2s, over the last few days, I've bled: the lift- pump, the secondary filter, the injection pump, and the injectors. It still won't start.

It's an engine that's been trouble-free for years, and started easily, and ran beautifully, just last week.

Now ....... where's my bleeding spray bottle got to?
Click to expand...
Definitely running on fuel in the system initially then the air arrives at the injector pump and the engine stutters as it runs on the irregular mixture through the intake and then picks up on 2. or 3 cylinders till number 4 kicks in at the end of the video. Might be a different matter if trying to start with an air locked injector pump.
 
Diesel injector pumps are precision components that rely on both naturally occurring compounds such as sulphur as well as other additives in diesel fuel as their only means of lubrication.

Unless it was a matter of absolute life or death I'd not contemplate trying to get an air locked diesel started by spraying fuel into the air intake whist cranking it because of the potential risk of rapid wear or premature failure of the injector pump from running it without any fuel inside for lubrication.
 
NealB said:
The engine in the video had, allegedly, run out of fuel.

On one of my BMC 2.2s, over the last few days, I've bled: the lift- pump, the secondary filter, the injection pump, and the injectors. It still won't start.

It's an engine that's been trouble-free for years, and started easily, and ran beautifully, just last week.

Now ....... where's my bleeding spray bottle got to?
Click to expand...
I cme up with an idea whilst servicing the PBO project boat. It has a VP MD 2020. I took out the bung on the top of fuel filter on the engine. Got the oil sucker outer pump, wound some electrical tape on to the suction pipe so that it fitted snugly in to the bung hole and started sucking with the pump. Two mins later, full fuel filters and the engine started instantly. Much better/easier than using the stupid lift pump that isnt very good. On older engines the suction pipe could be attached to the bleeding point in the injector pump.
 
AntarcticPilot said:
Isn't there a danger of pre-detonation (or whatever the equivalent is on a diesel)? Surely putting diesel in the air-intake means that it will burn as soon as the adiabatic heating of the air and diesel mixture reaches ignition temperature - which could be before the piston reaches TDC? And in that case, it's going to put stress on the crankshaft and con-rods. The point of the injector system is to ensure that diesel doesn't enter the cylinder until just after the piston reaches TDC.
Click to expand...
Just before tdc is the injection commencing point. Your point is a good reason for hesitating to use easy start. Interesting that its good on petrol engines becausethe relativelylow compression ratios dont allow it to bang ipunder compression, its the spark plug that fires it
 
It's a modern Kubota small plant engine. It has self bleeding injectors!

Fit the new lift pump, crack open the bleed valve on the injector box, crank it over for a few seconds, close the bleed valve. Start the engine. It may hunt a bit for a few seconds (as it does in the video), it may even die once or twice. But it will bleed itself in (strangely) roughly the time it took to stop hunting in the video

I have lost count of the times I've had to start plant on site which Paddy or Michal had run out of fuel! Even ancient Benfords and the like could be bled and started in less than a minute with practice

All they are doing in the video is adding a small quantity of diesel to the intake air. Chances are it's doing nothing at all to help get the engine going. Even if it is, it's totally unnecessary on that engine and as others have said I too would have concerns about the potential for engine damage
 
AntarcticPilot said:
Isn't there a danger of pre-detonation (or whatever the equivalent is on a diesel)? Surely putting diesel in the air-intake means that it will burn as soon as the adiabatic heating of the air and diesel mixture reaches ignition temperature - which could be before the piston reaches TDC? And in that case, it's going to put stress on the crankshaft and con-rods. The point of the injector system is to ensure that diesel doesn't enter the cylinder until just after the piston reaches TDC.
Click to expand...
The knocking at 2.17 caused by this method is something to avoid as it damages the engine.
 
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