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Discussion Starter #1 (Edited)
SD33 Blowing tons of white smoke - pic update

I had a problem today with my SD33 holding revs high. Basically it would idle normal, but when the I press the accelerator pedal the rpm would increase and just hold there even when I release the acc pedal. The revs would stay high and not return to idle unless I cut off the engine. Then idle normal again when the engine is started.

I found the problem to be a loose bolt on the vacuum side of the injection pump. This bugger here labelled IP Input. Its the line that goes from the throttle body, round the back of the engine and then into the IP



It was so loose that I was able to tighten by hand and the problem was solved, gave it a small turn with a crescent wrench to lock in place (cuz i didn't have a 17mm spanner).

Went on a test drive and the MQ performed pretty good. Essentially the IP has a vacuum line from the throttle that it uses to to adjust fuel to increase rpm

when I get back home (thankfully) suddenly she starts to idle rough and blow thick white smoke like a fog machine. so thick you cant see through the cloud of smoke. Engine is not cold as it was running just 30 min prior.



Its the same rought idle and thick white smoke as if the input of the IP is disconnected at the throttle (if you have done this you would know what I mean)



basically when the IP doesn't get a vacuum signal from this line it dumps diesel into teh cylinders so the thick white smoke is the result. I re-checked all connections and hoses and they seem intact.

I did a search and found this post that points to the IP diaphragm, but I don't think that is the problem as it was running perfect just a few minutes earlier

http://www.patrol4x4.com/forum/nissan-patrol-mq-mk-12/white-smoke-exhaust-when-i-release-throttle-75672/

What am I missing?

HELP :headwall:
 
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Discussion Starter #2
Update

Until now, i was convinced that the problem was the IP not getting a signal from the throttle.

opened up the throtlle vacuum line today at the throtlle body to clean and inspect and found this: a piece of rubber plugging the line




cleaned it out and then started it up but no luck. still blowing a lot of smoke

tried a bypass of the stock vacuum lines - no luck



then i opened the radiator to discover that it was dirty







looks like mud or rust

the coolant was all gone from the reservoir and the rad took about 1/2L of water

so I am thinking it may be a head gasket that is gone that is causing water to get into the cylinder

when it is idling it is idling faster than norm, although idle screw is backed out all the way
 

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Discussion Starter #4

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The color of the smoke doesn't look like water/coolant. I bet it is something with the pump or injectors.
 

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Discussion Starter #6
The color of the smoke doesn't look like water/coolant. I bet it is something with the pump or injectors.
that is the colour of the smoke on idle, on revving it is blacker

I bled all the injectors for about 5-10sec each

the injectors are new, installed Jan 2015 and prob have only done 2000km
 

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X2 diaphragm or maybe governor, keep looking into it. Any fluctuations in vacuum will change the fuel delivery massively. They're sensitive to tuning but easy to work with.
I had the same on a Toyota BJ42 years ago, left work one day and it was a fog machine. No one could follow me on the highway. Replaced the diaphragm $60 and sweet. Lube it with leather oil too not mineral oil.
 

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Give the smoke a good sniff,
Frequently, excessive fuel smoke will stink of diesel.
Engine oil, (broken rings) smells like oil,
And Glycol, can produce it's own smell....
 

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Discussion Starter #9
thanks for that tip

i'll go get high at next possible chance when i get home in daylight
 

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Discussion Starter #10 (Edited)
Update for you guys,

After several months of my Safari being down for this problem and not having the time or resources to have this looked at (such is the downsides of life of a project car at times), I was finally able to have her sorted out.

The problem was exactly what was mentioned several times here - the injection pump diaphragm was busted.

My mechanic identified the problem to be fuel delivery as soon as he saw her. When he removed the injection pump and sent it to the diesel pump specialist workshop, they were able to confirm that the diaphragm was busted as well as a couple other internal components of the pump were worn and in need of replacement, which was done.

I got the pump back all new and shiney



as well as a new hand primer pump



condemned the metal lines that went from the throttle body, around the back of engine and into the pump and used a new piece of rubber hose

radiator also had to come out to allow for the pump removal, so it got flushed and is now clean

much thanks to all who offered suggestions and advice,

My fat girl is back on the trails now
 

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Hello colleagues !! I'm new to you! And to me the same thing with some smoke .. And the slope does not have much power, it's like something, a diesel filter is changed.
 

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Discussion Starter #13
Did you get it repaired?
 
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