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post #1 of (permalink) Old 07-12-2009, 08:41 PM Thread Starter
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D40 turbo diesel engine issues.

Im having some issues with my 2.5TD D40 navara at the moment, its just started nowe the car is 60.000kms and 3years old, (just out of warranty)

Ive read about ALOT of similar problems on the net and spoken to many people that have had similar issues with their common rail navara`s.

For those that dont know, ill explain a little about the sorts of problems occuring. Some folks report a "severe loss of power", others call it "going into limp mode" or "safe mode" which is a more acccurate desription of whats happening. Somtimes the engine check light comes on, somtimes it doesnt when this occurs depending on whats causing the engine computer to trip itself into this protective state. When the vechile is in "limp mode" you cannot rev the engine much past about 2000rpm in gear, and there is very little engine power, even in neutral with your foot flat to the floor, you will only get about 3000rpm.
Simply swtiching the ignition off and then starting the vehicle again, resets the vehicle out of "limp mode" until the problem occurs again and so on....

The usual course of action then sees the poor unsuspecting punter down the nissan dealership asking them to find the problem where they come back and say "you need a new fuel pump and/or fuel rail, that will be $5000-7000 please sir"

Is any of this sounding familiar yet??? Well regardless, its time this BS from nissan stopped. For starters, a fuel rail (metal cylinder) doesnt just stop working, its a piece of metal ffs!. What the problem most likely is, is the fuel pressure sensor that screws into the end of it, and sends data to the ECU!! (or PCM they call it nowadays) Thing is, NISSAN ONLY SELLS THE FUEL RAIL AS A COMPLETE ASSEMBLY FOR $1000!!!!
Then theres the fuel pump, $4500 worth of high tech pumping technology that delivers 28,000psi of fuel presure to the fuel rail and injectors. Again, if your navara can happily operate for hours on end making great power, running like dream, chances are theres nothing wrong with you fuel pump, more likely to be somthing like a presure relief valve or fuel pressure regulator that comes with the fuel pump thats giving us dramas with intermittant problems yeah??? Thankfully NISSAN DO SELL THESE seperately for just under $400 last i called.

Now, after talking to a few people, it seems that YOU CAN GET a fuel pressure sensor on its own, just have to ask the right people who know where to get them OUTSIDE nissan, afterall the sensors are all made OEM by companies like bosch, seimens and denzo etc, in fact the whole common rail system is supplied by these companies.

It also turns out that there can many causes such as dirty fuel inc water etc, oil from the turbo on intake map sensor, corroded/poor connections and earths etc, that play havoc on these sensors and cause you ECU to trip out and go into limp mode besides just faulty sensors so check all of the easy stuff like this first, change you fuel filter, check for air leaks and fuel leaks neatral/park transmission switch etc.

Now im at a point where ive gone thru all this and here is my problem.
The car goes into limp mode when i leave it idle for more than about 30secs. I go to drive off and bingo, no power, no engine check light, no error codes logged in diagnostics (from the dealer). Apart from this, the car performs flawlessly non stop, drove 1200kms the other day without skipping a beat until i stopped at the servo and let it idle for 30 sec again same thing. So im thinking that at very low rpm`s, its tripping out on low or possibly high fuel pressure due to a faulty sensor or perhaps the regulator not controlling the pressure properly. I mean what else could it be???? everything else works...

So my next move is to order a fuel pressure sensor from a diesel shop that tells me they can get them, whack it in and see how i go. Failing that, im going to swap out the pressure regulator and then see what happens. I have a very strong feeling one of these things will fix my problem and so i will share the results with you so hopefully no more people will get ripped off.

end rant...
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