Hi Nailingtoon,

Sorry for the long post but there is a lot to say on this subject that you may be interested in, if not discard the following and have a nice day.

Cheers Damo.

I'm a mechanic and have been knocking around Diesel 4wd's and machinery for the last 20 years or so, so I have a bit of know how on this.

These days pretty much everything from your Cat Dozer or skid steer to the cheapest Diesel 4wd or car are electronically controlled either by common rail or by Electonic controlled injector pump.

This is mainly for the most point for emissions more than anything, secondly it is to allow for changes to the fueling for differing situations e.g. I live in Cranbourne at about 60m above sea level but often drive in the high country at 800 to 1000m above sea level.

A mechanical pump is set and where ever it's set is what it's set for within set perameters, so if I set it here on a Dyno down here and then I put it on my mates dyno in Mansfield, my settings will not be within the set parameters I have set down here.

With an electronically controlled pump e.g. early 2000 and up model 3.0ltr Prado's, have a very similar engine design to my Landrover Discovery 300 Tdi, just a little bigger capacity but an electronically controlled pump. The drivability at altitude is brilliant without the smoke that mine produces up there but doesn't down here.

You are totally correct on the reason you are sticking with the mechanical system, it's why I have stuck with my Landy for so long watching others change their cars often over the last 9 years and lose huge $ where mine has just had regular maintenance until the last 12 months where everything seems to be going wrong so is off the road for a rebuild at the moment but will be back on the road again around Christmas hopefully.

I wouldn't say that Patrol 4TD42's are bomb proof though. I have had a lot in over the years with fuel injector problems, quite a few injector pumps, Inj pump main drive keyway or gear giving out, Valve train issues, oil gallery issues causing main bearing failures and the list goes on, there is probably about a 50% chance or higher that the one you have now has had one of those problems wrong with it and the only one that doesn't actually stop the engine totally and turn it into a ride on a tow truck is the injector failure.

By the way, none of these problems are associated with lack of maintenance, they are all issues with the engine itself but that is nothing in comparison to most brands or the early 3.0ltr 4cyl patrols and Navara's.

Toyota is not immune from problems either, their good old 4.2 1HD turbo diesel used to crack pistons, oil starve the gudgeons on #1 on long hills, burn out valves, break rocker gear, kill oil pumps regularly but is still regarded as one of the most reliable engines ever made, which it probably is.

All engines have their good and bad points, your not over stressing an engine as long as it's geared correctly for the work it's doing and before all the mods you have done, that would have been my first. Drop the ratio a couple of points gives you much better pick up, de stresses the drive train and other than really high speed runs normally returns better economy when towing (in comparison to towing with standard ratio's).

Regardless of if I was modding anything and before I did anything else I would fit an intercooler, one that can handle a bit more HP than your expecting out of the engine as if you cooler is too small it will effect the HP big time but if it's too big it will stilll give you the maximum allowable HP and room for more mods.

This instantly gives you a HP boost and Torque boost along with keeping intake temps at a more consistent temp and allows for a bit more fuel and boost to be fed in and keeps the EGT's down.

Then I would play around with the exhaust to allow the turbo to spin up faster by relieving back pressure (which is all a larger turbo does).

Adjusting boost wont achieve anything much without adjusting fuel so unless your going to do this on a dyno and fit an EGT gauge, I would leave it alone unless you want a hole in a piston but if you are willing to spend the coin and put it on a dyno for half a day or so (at a reputable 4wd specialist of course) and fit an EGT gauge then go for it as the results will blow you away how well a diesel (especially the TD42) can go and how good economy you can gain.

Any mods will set you back $$$$ but they can be returned if you put in the miles but also be aware, anything you do to it may cost you dearly when it comes time to insure it and with VSI50 now in place, some mods may come under the banner of having to be engineered for registration in some states.

Just remember, the simple way is often the best, air out should equal 2.5 times air in, back pressure slows your turbo but you need a little, Keep everything clean and in the best condition possible, gear ratios should match the job, don't just expect that the current gear ratios will be adequate because that's what the manufacturer put in, they had no idea you were going to tow a 2.5 tonne van up and down NSW south coasts hills with your Suzuki Vitara .........EEEEK

So before doing any mods, think very carefully and consider what you are wanting e.g. more low down grunt to climb hills, better economy or high speed as this will determine what mods to make and what is not needed and how much it will cost thus how long it should take to return that cost to you if you are worried about that.

Electronics don't necessarily make a car less reliable is one of the points I'm trying to get across, remember when all cars had Carbys and then Fuel Injection started coming in.

I worked on an old school Toyota Corolla today with the Carby and the 100 or so rubber hoses going to all sorts of mysterious places. I't funny, it took some thinking to remember how it worked and where things were but eventually sorted it out.

So when the Injected cars came in, Old School guys like me started to panic a bit but then I realised that I could use my electronics background from a previous teenage early twenties life in the early days of networking computers and get ahead of the rest of the crowd.

This was good in theory and worked for a little while but it all changed so fast that specialists started popping up all over the place which for us ended up being a far more affordable way for us to have it diagnosed due to the hundreds of slightly different types of systems that were around then.

These days things are a bit more simple, a workshop only really needs a laptop and some cable sets and maybe a handheld diagnostics machine and you can do about 90% of what's out there, the rest is done with a common Multi Meter or test light and it's normally pretty simple as most of what goes wrong is normally sensor related so sometimes it's a matter of going and finding a broken or crushed wire or a blown fuse and sometimes the actual sensor may be at fault but most of the mechanical and electrical/electronic components are very reliable.

Well I hope my long winded ramble may have enlightened some of you and dispelled some fears in others if not, I will try next time to return your lost time with interest with something really helpful like how to empty your porta potty without lifting anything heavier than a beer or maybe how to..........I'll keep you guessing.

Cheers Damo

thanks for that damo nice to see other other opinions i think any subject like this is useful to most of us, and like i said and i am a bit biased always been a nissan man ive had good offers for my 4.2 td patrol but have no intention of selling it, it has already done the big lap and will be off again next year

Neil

I would love a Patrol personally as generally I have found that they require a lot less maintenance to keep on the road than my Landys (Disco Series 1, 1 Duel Fuel and 1 TDI)and are a very comfy and roomy old bus which suggests the only thing I don't like about them.

We used to have an 80 series Cruiser before the Tdi Landy and my Mrs struggled to park it in a standard car park between 2 cars as it was very long and wide which is what I also find driving patrol's.

But then again, my CF60 Waeco only just fits long ways in the back of the Disco and there is very limited luggage space which would be a really nice change with a patrol as would having the extra grunt from the 4.2.

Just pointing out that no matter what it is, everything has common issues and problems, so there are very few reasons that you would avoid the newer model 4b's other than the obvious.........$$$$$$$.

Thanks Mccanic. We've just posted a thread about fitting a Steinbauer chip to our NT Pajero. Basically we're after a little more power towing uphill and better fuel economy as we're planning a big trip next year. You've given us some food for thought!