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Nissan Navara D22 ZD30 Black Smoke and Low on Power

Nissan Navara D22 ZD30 Black Smoke and Low on Power

635 318 Brooke Hamilton

Nissan Navara D22 ZD30 Black Smoke and Low on Power

The ZD30 have a VP-44 fuel system, which feature an electronically-controlled traditional-style fuel pump. With the electronic control, there is finer tuning of engine timing throughout the rev range, and ultimately these pumps simply wear out. The main failure is the fact the engine can no longer reach full advance.

What ends up happening is the engine is obviously therefore retarded, and because it is retarded it is no longer making power efficiently. The driver then puts more throttle in and effectively you end up with a situation where the engine is now over-fueling. One check that can confirm is looking at the spill valve percentages. A new pump or a decently equipped setup is somewhere in the order of 50-70% in terms of spill valve percentage. At hot + idle, a dead pump will be anything less than around 20%, and generally you start to see symptoms at 28% and lower.

The way the timing works inside the pump is effectively governed by the internal pump pressure. It’s also worth noting that this internal pump pressure can be influenced by outside factors. The most common one is usually aerated fuel supply. If the fuel supply to the pump is aerated the pump cannot compress the fuel properly, which means it won’t get a decent internal pump pressure, and therefore can’t get internal pump presure. It’s highly important that it’s without air and it’s also important the fuel flow to the pump is unrestricted. If you have a big vacuum on the pump-supply side, then obviously the pump isn’t getting the fuel. It’s losing internal pump pressure and therefore losing advance.

So first thing, always check the spill valve percentages (sometimes called IC percentage). We always have a clear piece of fuel line with a T-piece to a vacuum gauge, and we just attach that on every car. It takes five seconds or five minutes to go for a quick run around the block to make sure there’s no air or vacuum in the fuel supply. This one quick step is the most vital to ensure a few thousand $$$$ is not lost in a miss diagnosis.

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6 comments
  • Lee Mcintosh

    Mine is blowing white smoke and low on power. Also needs to be primed by pumping the filter to start it most of the times. we have put clear piece of fuel line in and does not seem to be any air in line. Does it sound like Fuel pump problem?

    • Matt Baileys

      HI mate,
      Yes its quite possible. Do you have access to a scan tool at all? a quick check of the IC % (or Spill valve %) will confirm the diagnosis. New pumps will have a IC % of 50-70%, they’re ‘ok’ to around 28%. To be blowing white smoke, I’d imagine the number would be much lower – around or below 10% even.

      Also, its worth putting a vacuum gauge on the fuel supply, as its possible there is a restriction without there being air.

      Hope this helps – and make sure you post your results once you solve it (or ask more questions if you dont! we’re here to help!)

  • muzza

    hi fella
    I have 2010 3lt patrol 118000km it blows white vapour /smoke in the morning or when been sitting for a while, but does’nt do it all the time. I have been to some big name mechanics but never dose it, its got poor fuel economy and blows black smoke. what do you think it could be.

    • Matt Baileys

      Hey Muzza,
      Pretty rare to be getting black smoke and poor fuel economy in a ZD30 CRD> they’re usually one of the best. First step would always be getting it to a competent mechanic (with these things) for them to review the Boost, injection volumes, Rail pressures and the like. Almost always, we can see the fault manifesting itself here (but not always the cause)…
      Hope this helps

  • Kel

    Hi I have a crd zd 30 patrol that is impossible to start when the motor reaches operating temperature. At about the same time as this problem developed the no4 injector was leaking fuel in the vicinity of the rail pressure sensor and the oil pressure sensor. The leak was fixed and we drove from Darwin to home in queenslands south east with the oil light on. Any sugestions as to the hard starting problem.

    • Matt Baileys

      Have the injectors checked for leakback volume (can be done on vehicle). Very common fuel system failure is for high pressure to leak to low pressure resulting the pump basically not being able to provide enough fuel whilst cranking to start. May not be it, but would be my suggestion.

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