broken turbo

[West, David]

Hello All

Thanks to those of you who replied to my queries.

I have since bypassed my turbo which made no difference. So therefore 
that should be ok.

I checked the compression again, which was all within 5 PSI but the 
plugs smelt very fuely  . They looked oily but when the fuel 
evaporated they remained sooty - I am pretty sure I have a fuel 
problem.

I checked my hot wire flow meter on the bench. It is within spec both 
statically and dynamically but dynamically with the vacuum cleaner 
going, the voltage is 4.0 volts which is the max allowable but the 
flow from the vacuum cleaner would be somewhat less than the engine I 
would have thought. Based on this, I reckon that the flow meter is 
telling the ECCM the wrong info and the ECCM is then injecting more 
fuel than required.

The engine is a stock aussie holden VL commodore turbo, nissan RB30 
straight 6 cyl 3 litre.

I am getting injector pulse width of 2.4 msec at 1000 rpm. This is 
more than 1/5 total width. Based on an engine that produces 200 bhp at 
around 6000 rpm this means that I am injecting enough fuel for about 
40 hp. This can't be right.

Does anyone out there know what an approximate pulse width at 1000 rpm 
would be for an engine like this one.

Regards,


David West

-----Original Message-----
From:	Fredrik Skog [SMTP:c95fsg at cs.umu.se]
Sent:	Friday, 18 December 1998 20:12
To:	West, David
Subject:	Re: broken turbo

On 18 Dec 1998, Tom Parker wrote:

> West, David <djwest at subcorp.com.au> wrote:
>
> >If a turbo housing failed in some way near the oil galleries is it
> >true that you generally only get oil into the combustion chamber 
when
> >under vacuum conditions where as boost will pressurise the oil
> >galleries? Secondly, when this oil burns will it be mainly whitish
> >smoke? Thirdly, should this oil be present throughout the intake
> >manifold or is it fine enough mist that it is hard to detect.
>
> I have had experiance with Minis sucking up oil through their crank 
case
> breather system. When a Mini with the right type of breathers goes 
hard round
> a corner the oil can get thrown into the breathers and it goes 
straight into
> the inlet manifold. If this happens you get huge clouds of white 
smoke. If the
> rings have gone, then you get blue smoke.
>
> I don't know about turbos, but large amounts of oil into the inlet 
manifold
> can produce white smoke.

I run my turbo engine without valve seals on the exhaust valves, 
because
they don't get enough lubrication othervise. On every startup this
produces a large cloud of white smoke due to oil running down the 
valve
shafts into the cylinder.


> --
> Tom Parker - tparker at nznet.gen.nz
>            - http://www.geocities.com/MotorCity/Track/8381/

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