'00 jackaroo 3.0l turbo diesel

Hi Baz & Kaz,
Sorry to hear of the problems, especially with a 'recently purchased' vehicle. I'd hope the workshop has already checked all this but I'd start with fuel filters and sedimenters, etc. Drain the sedimenter (if fitted), replace the filter(s) (if not already done) and make sure everything is done-up properly to prevent air leaks.

The 'missing' when you ease-off the throttle is puzzling - normally any fuel starvation or air ingress will cause problems when accelerating hard. Does it 'miss' only if you gently ease-off or does it also happen when you suddenly lift-off the throttle? If only when gently easing-off, it could perhaps be 'hunting' by the injection pump. (I don't know whether the Jack's pump is fully mechanical, electronically-controlled or a hybrid).

Another thing to check is the turbo wastegate tubing. Make sure all the tubes and connections from the pressure sensing point (normally at the turbo air outlet) to the wastegate and/or the injection pump are sound. If the pump has a mechanical boost compensator, it could be getting it knickers in a knot on load changes, if there're any air leaks in the tubing.

If nothing shows, I'd be heading for a diesel injection pump specialist, not a general mechanical workshop.

Hope this helps.

Hi Baz and Kaz

I owned a 98 3.0 lt turbo diesel that showed similar probs to yours incl refusing to start some mornings - engine would turn over but not fire. There should be some archive history on this site. I was then referred to a motor vehicle recall site where thw holden Jackaroo was posted for recall to rectify prob. If yours has same prob then it came down to the holden dealer replacing a wiring loom connected to the oil pressure sensor on the engine block. My sensor ws leaking oil into the wire loom . This fixed the prob. Hope this is of some help.

Johnno

They are an efficient, powerful but damned sophisticated engine. The injectors are driven by oil pressure from one of the TWO oil pumps, then actuated by electric impulse. The accelerator pedal drives the actual throttle body by wire. And the computer is coordinating the lot, as it gets input from a number of sensors. If you have all the basics covered as suggested by Ian, the engine management analyser (" the machine that goes ping") at the dealers workshop may be the only hope. Guess you may have done that. The issue may not show up anyway. Having the valves and injectors sorted is not all loss anyway....think of that as an investment :-) There has been a post awhile back where some poor sod had paid many thousands while some cockhxxd of a mechanic kept changing expensive components in the hope that one would fix the issue he had - any fool can do that. Happily, my 99TD SE is still running fine.The trick is to find someone who wants to help you, as opposed to fleecing you. Which oil do you use ? It matters. Which area are you in ?

Understood - its a bugger - expertise is the issue - the dealers often don't have it (they just consult books, manuals etc like we do). Its the very same on the north island in the cities too, be assured. Short of an Isuzu factory technician from Japan, what to do ? One thing I do know is that as soon as you take your foot off the accelerator while mobile, the injectors shut down completely (to save fuel and to aid in braking I guess) - they only come back on when the engine slows to the point of idle, or you re-apply the accelerator. The throttle body or something else in that circuit must be turning them off in this situation. Maybe they are not turned off effectively ? Maybe running partly - erratically, on deceleration ? Re the oil comment - seems the "happy Jack owners" are using 10W-40 for mild climates, 5W-30 for cold conditions, and 0W-30 for frosty conditions. Unfortunately, the Jack is a bugger to start in cold weather and oil viscosity plays a big part in the process, along with a good battery (700 CCA if a single system) - the new ones have 2 batteries now, I understand.