Leaky Diesel Injector

citronut · Post by **citronut** » Thu Nov 05, 2009 7:38 pm

leak off pipes and end caps are so easy to do its best to try them first before getting all technical

regards malcolm

Post by **docchevron** » Fri Nov 06, 2009 2:33 am

It's hardly technical.

If it leaks at the joint (where the two halves of the injector join) then it's not hard to put a spanner on the top part of the injector and give it a tweak (handily both bosch and Lucas injectors have flats in the top of the injector body for just this very purpose!).

BX Bandit · Post by **BX Bandit** » Fri Nov 06, 2009 4:58 pm

I thought I had this problem a few months back - a leaky injector that is. In the end it was the leak off pipe or end nipple but as they were new I removed the injector and tightened it up some. Bloody annoying to do all that and for it to be leak off

That does bring me to another point though, I had separated the injector halves to clean them up etc (although they were all very clean inside anyway

) but what is the correct torque to tighten the two halves back up?

Post by **docchevron** » Sat Nov 07, 2009 2:07 am

Ahh the torque setting required there is "Tight".
No idea TBH, I usually just do them up so the thread doesn't strip, if it does, I know I did it up a tad too tight...

BX Bandit · Post by **BX Bandit** » Sat Nov 07, 2009 11:15 am

Well, I did do 'em tight, but then re-tightened the one that I thought was leaking....but that means that one injector is done up tighter than the others which surely means the internals are compressed that little bit more leading to lift pressure differences across the 4 injectors...

Ian_Fearn · Post by **Ian_Fearn** » Sat Nov 07, 2009 11:30 am

I replaced the leak off pipes today and found one was split. Also the cam cover gasket was split and leaking so replaced that too.

The injector was seriously tight, no way that was going any further without causing damage.

Thanks for the advice.

Ian

Post by **docchevron** » Sun Nov 08, 2009 1:11 am

BX Bandit wrote:Well, I did do 'em tight, but then re-tightened the one that I thought was leaking....but that means that one injector is done up tighter than the others which surely means the internals are compressed that little bit more leading to lift pressure differences across the 4 injectors...

Yes, this is true.
Can't say I've ever noticed any adverse effects mind.
I've only ever done them up by feel, but I guess it would be the done thign to go find out the correct torque setting!

I'll ask the guys on monday..

BX Bandit · Post by **BX Bandit** » Sun Nov 08, 2009 9:54 am

Yeah, it'd be nice to know. As you say, the differences will be small, but when you consider what we spoke about (can't remember when!) injectors getting 'tired/worn' partly due to spring fatigue then I would of thought an extra 1/8th of a turn would make more of a difference.

Then, when you consider the differences in cylinder pressures you'd of thought that the differences are more than large enough to offset spring fatigue and 'injector torque ups' put together (although cylinder pressures and fuel atomisation are two completely different things)

(sorry to those who find this dull or incredibly anal!)