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2H Very smokey, any ideas???

Posted: Fri Jun 04, 2010 3:14 pm
by McGark
Hi there,

I have a 1987 HJ75 running a 2H motor with an ARB turbo. I have just moved to a colder climate (Jindabyne) and put winter mix in her.
The problem is that when I come down hill (i.e. engine braking) she blows a MASSIVE amount of white smoke, when I give her a stab of throttle then let off again it's black then white. I beleive white smoke is unburnt fuel? But don't really know why it's doing this. I'm not sure if it's the winter mix - it was doing it before but it's just gotten a lot worse.
Any ideas? I'm not sure if driving it like this will crack the head or worse if there's a serious issue... please help!

Posted: Fri Jun 04, 2010 4:02 pm
by luk3y
mine does the same thing in my 60 with a turbo 2h i was just about to post the same thing up please help!

Posted: Fri Jun 04, 2010 4:29 pm
by oldmate
Could be a leaking injector. the 2h runs a butterfly valve on the intake so when it's closed it creates a vacuum. No air = no or partial diesel combustion = white smoke!

Posted: Fri Jun 04, 2010 7:30 pm
by BadMav
The butterfly valve/ throttle plate in the 2h diesel has a big notch in the side of it where a venturi is in the side of the throttle body. That's what creates the vacuum. The 2h does not create enough 'manifold' vacuum to operate the fuel pump diaphragm effectively. So really it doesn't do anything to hinder the air intake to the motor at all. If it did all it would do is make it chuff black smoke as it would be running too rich, which it wouldn't because of the venturi effect drawing even further back on the diaphragm and fuel rail.

A common problem with the 2h turbo running boost levels higher than around 10 psi is the governing diaphragm receives a boost signal when the throttle is closed or partially opened. To overcome it on my 75 ser it required a complex and well thought out system of restriction fittings and check valves to tell it to give it fuel when I wanted it to.

I would suggest you check the pump timing and check your compression. This would be more likely to produce unburnt fuel.

Posted: Sat Jun 05, 2010 9:20 am
by McGark
Thanks fellas, I'll have a look into those things.
So can I rule out the winter mix as a problem, just coincidence? Old mate reckons the winter mix is about 50% heater oil (and good for your rings) and if anything would be creating more black smoke but not the white...

Posted: Sat Jun 05, 2010 9:34 am
by BadMav
Black smoke= overrich fuel mixture
White smoke= unburnt diesel
Blue smoke= oil smoke

Posted: Sat Jun 05, 2010 11:22 am
by Punchy
also check your not loosing any brake fluid.

Brake fluid burns white as its drawn in and burns.

Old Brake boosters can fillup gradually with a leaking master cylinder

Posted: Sat Jun 05, 2010 12:11 pm
by dumbdunce
torn/leaking governor diaphragm?

Posted: Sat Jun 05, 2010 4:56 pm
by McGark
cheers for your suggestions, just a dumb question - how would brake fluid be getting burnt and gong through the exhaust? Also I've heard that running incorrect fuel mixtures can seriously F$%# things up blown head etc. Is this smoke issue anything to be concerned about?

Posted: Sat Jun 05, 2010 8:07 pm
by BadMav
Highly unlikely but if the vac assist diaphragm (the big black round thing on the fire wall with the brake master cylinder on it) is leaking AND the master cylinder is leaking theoretically brake fluid could be drawn into the intake through the vacuum feed line. I've had brake fluid drip ON the exhaust before, yeah bellows white smoke. Too much fuel will melt pistons and head gaskets, yes, bad. As for the white smoke, it won't hurt anything except your fuel economy, as said before get the timing and compression checked.

Posted: Sun Jun 06, 2010 3:09 pm
by oldmate
BadMav wrote:Highly unlikely but if the vac assist diaphragm (the big black round thing on the fire wall with the brake master cylinder on it) is leaking AND the master cylinder is leaking theoretically brake fluid could be drawn into the intake through the vacuum feed line. I've had brake fluid drip ON the exhaust before, yeah bellows white smoke. Too much fuel will melt pistons and head gaskets, yes, bad. As for the white smoke, it won't hurt anything except your fuel economy, as said before get the timing and compression checked.
That can't happen on a diesel. vacuum is generated from a pump on the alterator on a 2h, not the manifold

Posted: Sun Jun 06, 2010 3:57 pm
by BadMav
Deeeer, yeah oldmate, you're right. oops.

That could only happen on a petrol engine deeeeeeeeeeerrrrrrrrrrrr I got i wooden spoon!!!!!

:drinking: :drinking: :drinking:

Posted: Mon Jun 07, 2010 11:08 am
by McGark
yeah true, She wouldn't start this morning - I think I need new glow plugs, so I'm going to go to the local mechanic and see if there is a common cold weather problem with deisel engines down here - I came from Cairns and things have gone downhill since being in coldland - I'll let you know the outcome. Thanks again I'll keep you posted

Posted: Mon Jun 07, 2010 2:00 pm
by oldmate
Your glow plugs are probably no good too, but they only cause starting problems.

Rule out the head gasket first. THat's easy.
1 is it loosing coolant,
2 is it bubbling in the radiator?

Being a turbo'd 2h the head is under more stress than it's really designed for so it is a possibility.

however if the cooling system and hg is fine i'd still be looking at the injectors.

Also are you sure it's white smoke and not a blueish white smoke? because the latter could be oil sucking past the valve stems, which can happen with high revs and no load like coasting down a hill.