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Bonus - Jackaroo Manual
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Injectors fail to fire

This is a hard one to be sure about, without resorting to a TECH-2.

However, it must be remembered that for a “start” to occur, there are a series of pre-existing conditions:

  • There is fuel to the front of the oil-rail;
  • There is oil at full pressure to the oil-rail;
  • The oil does not smell of diesel;
  • There is no coolant in the engine oil;
  • Enough power to turn the engine over;
  • Power to turn engine at > 250rpm;

If all of these issues above are OK, then to achieve a start, a number of other things must also occur:

  • No leaks via the o-rings of injector to the oil-rail;
  • Sufficient oil in the engine;
  • Correct oil type;
  • Bottom [sump] o-rings OK;
  • Flow of oil from the HP oil pump into the connecting HP-oil pipe;
  • Sufficient CCA in the battery and at least 11.8V;
  • Operating RPCV valve;
  • Operating ORPS


The ORPS does not give any indication of failure and the cutting of the “white-wire” or installing a switch in the loom to manually disconnect the ORPS will determine if the ORPS has failed. If it is an ORPS failure cutting/ disconnecting the wire to open circuit tricks the ECU into enabling the injectors.

If it is an ORPS failure, you cut the white wire, the engine will fire = ‘limp home” mode and then replace ORPS and fix the wire or put in a switch.


This valve also gives no indication of failure, but if the bottom nut of the HP supply pipe is cracked open with a 27mm spanner, the engine cranked over and a reasonable quantity of oil emits from the pipe, the RPCV is OK.

Still, probably worth cleaning out [with extreme care] and exclude this as a problem, particularly if the trucks history is unknown, or there has been diesel in the oil following a failed injector. Often following an injector failure, the degradation of std. Holden o-rings, which are of relatively low quality, will leave material in the HP oil circuit and bits of the o-rings and other “grunge”, will lodge in the RPCV.

If all the above conditions are met, the injectors will fire, the engine starts and runs.



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