injectors

[Oxford Landing]

Hi

I have a JP3 starts and runs perfectly, but I have a fuel leak from the top of my injectors well 2 of them, all is OK if running with low revs I have no leaks, but run with high revs they leak!! the exhaust runs clear (well some smoke I think is normal) but every now and then I get excess smoke and fuel drops on the roof and out of the bottom of the exhaust joint and just as a side issue but may be connected I have started to see some air bubbles around the valves in the head oil bath any suggestions?

[martyn 1]

I believe we spoke about this yesterday, As I said, if you have diesel coming up around the feeler needles in the top of your injectors then they are in need of repair, an intermittent poor spray pattern/dribbling injector would cause most of the issues you are seeing. Get the injectors sorted first as its an obvious issue then Identify if any of the other issues you have are related or not. I believe you mentioned that you had tried a different set of injectors and all was OK which is a big point towards faulty injectors.

 

Kind regards

 

Martyn

[RLWP]

Beat me to it Martyn - get your injectors serviced.

 

You already have an obvious problem with the leak from the top of the needles, in fixing that you might sort the rest

 

MORE: Another thought - how is your spill rail arranged? Those needle topped injectors really should be spilling into a collector pot of some kind. Are they connected to the fuel feed circuit somehow

 

Richard

Edited May 7, 2015 by RLWP

[frangar]

Hi

I have a JP3 starts and runs perfectly, but I have a fuel leak from the top of my injectors well 2 of them, all is OK if running with low revs I have no leaks, but run with high revs they leak!! the exhaust runs clear (well some smoke I think is normal) but every now and then I get excess smoke and fuel drops on the roof and out of the bottom of the exhaust joint and just as a side issue but may be connected I have started to see some air bubbles around the valves in the head oil bath any suggestions?

 

 

What the others said!

 

Ive used Peter Slater Injection Services in Scunthorpe for servicing mine. He does them by post if you cant get there

 

Although the air bubbles round the valves might point to a possible head gasket issue….but get the injectors done first and then see what else happens

 

Cheers Gareth

(Proud owner of a JP2M)!!

[by'eck]

 

 

Although the air bubbles round the valves might point to a possible head gasket issue….but get the injectors done first and then see what else happens

 

Cheers Gareth

(Proud owner of a JP2M)!!

 

I was tempted to suggest valve guides.

[Oxford Landing]

Thank you all, I had spoken to you Martyn and you gave me great info and your time, just thought someone might have a similar fault before I take out the injectors and send them for repair. the return from the injectors to the fuel tank is clear, will let you know the outcome.

[frangar]

I was tempted to suggest valve guides.

That would still be a head off job though......I think

 

Cheers

 

Gareth

[Timleech]

Thank you all, I had spoken to you Martyn and you gave me great info and your time, just thought someone might have a similar fault before I take out the injectors and send them for repair. the return from the injectors to the fuel tank is clear, will let you know the outcome.

 

Is the fuel tank below the engine?

If not and if the leakoff is returned to the tank that could be contributing to your problem.

The original design was for the leakoff to run by gravity into a little container. If there is positive pressure in the leakoff pipe, leakage is more likely, especially so if you have the original style of injector with the needle in the top.

 

Tim

[RLWP]

Thank you all, I had spoken to you Martyn and you gave me great info and your time, just thought someone might have a similar fault before I take out the injectors and send them for repair. the return from the injectors to the fuel tank is clear, will let you know the outcome.

 

You shouldn't have a return to the tank, unless the tank is below the injectors and the return pipe is separate from the fuel feed

 

Richard

[Timleech]

 

You shouldn't have a return to the tank, unless the tank is below the injectors and the return pipe is separate from the fuel feed

 

Richard

 

Glad to have my opinion confirmed

 

Tim

[RLWP]

 

Glad to have my opinion confirmed

 

Tim

 

Naturally, I found out the hard way...

 

Richard

[Oxford Landing]

The fuel tank is below the injectors and a separate return, easy to disconnect and try, the injectors are original type injectors with needles.

[RLWP]

The fuel tank is below the injectors and a separate return, easy to disconnect and try, the injectors are original type injectors with needles.

 

That's fine. What you can't have with those needle topped injectors is any kind of back pressure on the spill return side. Otherwise they leak through the top

 

Richard

[Dave Clinton]

 

That's fine. What you can't have with those needle topped injectors is any kind of back pressure on the spill return side. Otherwise they leak through the top

 

Richard

As a follow up - is there any problem in general on air cooled listers, SR, HA etc, with returning the spill rail to the engine mounted fuel filter?

[Giant]

Interesting to read this advice about the spill lines. Our JP3M spill currently goes back to the tank which is well above the engine. Should we change that? Our injectors are the later type without the needle in the top.

[Roadsteam]

HR, ST etc, no problem with returning to the filter, its how ours were piped from the factory.