Leaking Fuel Injector

[donncha]

I have a Yanmar 3gm30 and recently I have discovered that when the engine is running a quantity of diesel leaks from the middle fuel injector onto the surrounding area and down the side onto the starter motor. This is cause for great concern and I am wondering if anyone has experienced this sort of problem before? I shall go about removing the injector and checking washers and the like but does anyone have any advice about this operation? I will of course consult with the manual before messing about with the injector.

 

[steve28]

the engine will not be running smoothly if the leak is on the high pressure side, check to se if its the high pressure pipes or the banjo copper washers what are causing the problem, i use toilet paper but only after the engine is stopped.
The copper washers can be anealed by holding them in a gas flame until glowing then drop into cold water.

 

[PaulJS]

When you're working on the fuel system the golden rule is cleanliness. Also I'd recommend using new copper washers if possible. You can easily anneal the old ones, but if it's leaking due to a particle of dirt or something being trapped the washer may be damaged.
Good luck, I hope it is something simple.

 

[PaulJS]

Sorry Steve, I was posting at the same time as you, didn't intend to sound contradictory

 

[Heckler]

Why are you removing the injector? If it is a fuel leak removing the injector wont solve anything, just dry it off and use tissue paper to check where the leak is, it will be from the leakoff connection or the high pressure nut.
Stu

 

[donncha]

As far as I can tell it's from the high pressure nut. If i loosen off the nut what should I do then? Inspect the washers and perhaps replace them? Tighten the nut up more?

 

[earlybird]

As I recall my 2GM20, there are no washers sealing the HP pipe to the injector body, just a flared pipe giving a metal to metal seal. All you can do is tighten it, but don't overdo it. If leakage persists, detach the pipe and carefully examine the flared end.

 

[Heckler]

If its from the high pressure nut you can only try tightening a bit, there arent any washers in there, only a tapered olive type fitting. If it is too tight it has probably been overtightened and the taper damaged, in that case a new injector pipe (the nuts are captive on them) will be called for. Try undoing the nut and have a close look at the mating tapered faces to see if you can se any distortion etc.
Stu

 

[donncha]

Thanks. I will check more carefully with the aid of paper next chance I get. From what I could see though it could have been that the fuel was leaking where the valve itself connects to the engine.

 

[Billjratt]

Valve?
Maybe a more experienced neighbour could be coerced into having a look. Don't over-tighten otherwise you will need to change something.

 

[Heckler]

Not impossible for the injector body to leak but highly improbable. Check with tissue paper to pinpoint before ripping apart.
Stu

 

[donncha]

[ QUOTE ]

Valve?
Maybe a more experienced neighbour could be coerced into having a look. Don't over-tighten otherwise you will need to change something.

[/ QUOTE ]

Sorry I meant to say the fuel injector nozzle itself. I wasn't referring to the valve inside it. I have the tightening torques in the manual.