Originally Posted by
Superjuice2072
Hi Everyone,
Ok... where to start... firstly, please correct any information in here for others wishing to learn, if you feel this content is slightly incorrect as described, for NEW ZD30 owners may need to know some of this stuff... and I wouldn't want them to get a wrong tangent from me...
Since November (Simpson Desert), I've been having problems, as described previously in this thread. Suffice to say, they have been frustrating and stressful, especially when you have a large fiscal figure hanging over your head ($4000-$8000) to fix the injector pump, and yet I've sensed that there was nothing wrong with the pump. So the pressure has always been, from numerous people and so called specialists, to pull out the injector pump OUT, OVERHAUL, and supposedly, voila... problem fixed!
As I've said previously, Chaz has been an enormous help to me, so I really want to acknowledge his input into this and the solution I've found for my own vehicle/troubles, and hence the learnings I've received, so to speak...
November... warning light on dash frequently coming ON... no power... limp home to east coast QLD... Nissan dealership review for $150, suggesting injector pump failure... January second opinion... another "Specialist injector pump 4WD service centre on the Sunshine Coast" $350, suggesting the same thing... February-March reading Patrol forums, talking with people, researching the net, trialling a number of fault finding tricks and YIPEE, the vehicle seems to be running perfectly again... so far, it IS running perfectly... will keep you informed if this changes... otherwise, ALL GOOD!!
1. Placed a Walbro lift pump to vehicle - Outcome - vehicle was still running poorly frequently to infrequently, but I seemed to have some hope that it might be helping the vehicle overall - Pump has been great for priming the fuel filters and for positively pressurising the fuel lines to check for leaks - found a very small weep of diesel up around the filter head - so fixed - easy
2. Changed out at least 2 fuel filters since November (1000-3000klm) - first replaced out Wilpena Pound - it looked like it had dirt in the fuel that was removed - not heaps by my experience, but nonetheless, looked like red dirt - replaced second fuel filter yesterday just because I was getting more desperate to fix this vehicle - I initially thought the first filter change would be sufficient, at the time - again, another Nissan fuel filter placed in yesterday - seems to be more red dirt in the filter coming out - no rust - so I may need to replace this fuel filter AGAIN in time to come soon - will see... talking with Chaz, experience suggests that the ZD30 may require MULTIPLE fuel filter changes before problems resolve - so, always be mindful of MORE than one fuel filter change Lindon...
3. Oil level in sump, and hence on the dipstick, MAY be increasing... not sure yet... but will continue to review... talking with Chaz, if this IS the case, diesel may be leaking into the motor, thus affecting the quality of oil and lubrication, not to mention volume in sump... will need to check oil before starting from now on for a few months, to check whether the oil level is increasing, compared with decreasing... my understanding - fuel goes to injector pump - fuel then to injectors - remaining fuel (now HOT) that is NOT used during combustion returns to fuel INLET side of pump via return line - there is a "spill line" where diesel can make its way into the rocker cover, and importantly, can also suck air back down into the injector pump, thus air going past sensors to give a FALSE reading of injector pump failure... now, my explanation of spill line, etc might be a little naive still, but suffice to say, this is a vital piece of information to know about these ZD30s... thanks Chaz... this can be fixed with a number of inexpensive parts and small modification... and if the fuel continues to leak into the oil level, then at least I know how to fix it in the future, by pulling the rocker cover OFF, and finding the leak, and fixing...
4. Now, other than the fuel problems as above, and replacing fuel filters, I decided to place a new MAF sensor and new air filter into vehicle anyway... I will continue to mix/match the older air filter and MAF sensor over the next few months to see what happens... these two were still in good condition by the naked eye, but changed them to see whether there was any improvement...
5. I also had a secondary problem which had to be found... there had never been a lack of boost at any point, until just the other day, so I pull the inlet off the turbo and viewed... ran the vehicle at idle and the turbo fan spun fine... the fins appeared ok and the spindle was firm with NO play... because I have vacuum hoses going everywhere with Dawes boost controller and needle valve, I checked all the lines, hoses, intercooler & hoses, etc... during the mission I found the hoses good and the vacuum pump working, so pulled the Dawes controller apart to find the small stainless ball was stuck against the rear of the housing, due to a very small amount of oil that had migrated into the line, DESPITE the catch can... is there any way to further reduce the amount of oil that comes back into the air intake, other than the catch can I have already?? Don't know... but it pays to check these every now and then and clean them with something... so that fixed the lack of boost and obviously the rise in EGT...
I realise this is long-winded, but I have found the more I read on the forums, from those who you can trust, the more you can gleam to solve your own problems... thus, I wanted to waffle a bit and expand in some areas to give a flavour of findings, instead of just cold hard fact, which is hard to comprehend and decipher what is happening... feel free to ask questions if you are having problems with your own vehicle, if exactly the same as mine experienced...
Learning so far:
1. Change all filters, especially fuel filter - fuel filters may need to be changed multiple times over a short period
2. It's great to have a new MAF sensor to change IN/OUT to review the present one
3. It's great having a Walbro lift pump to supply positively pressured fuel to the injector pump and to the filter head
4. I've had a water separator on the vehicle since last injector pump build... that has been important
5. I don't have any other fuel filters inline, so that fuel FLOW is NOT restricted to the injector pump
6. Fuel can leak into the rocker cover... so need to check oil regularly, NOT for low oil, but for HIGH oil levels... if needing fixed, it will be a cheap fix by comparison to an injector pump
7. Oil can still make its way back into the vacuum hoses and foul the Dawes controller
8. It's important to have at least one boost gauge and a pyrometer in the ZD30 to monitor the engine, as a bear minimum. These have been invaluable in fault finding the problems too...
9. Don't believe everything Nissan dealership, mechanics, or specialists say... Talk with the real specialists on the forum here... the ones that really DO know these vehicles inside out... I am a paramedic by trade and still learning a lot about diesels, ZD30s, electrical, etc etc... but if I worked it out over a few months, surely there must also be some other people replacing injector pumps for no need too...???
10. There are miscellaneous others, which are important also, but figure I best stop talking and get off the forum, before you guys kick me off...
Hope my waffle may help some other poor fella out there having problems too... I am looking forward to some 4WDing out Landcruiser Park and Glasshouse now... once the rain stops !!
All the best... I'll post more over the next few months...
Lindon
Attachments are just simple visuals of engine bay... nothing exciting... but gives new people something to look at... I really like pictures and visualising layouts...!!
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