Having owned a Yr2000 Discovery, my first Land Rover, for only 6 months, I was quite keen to find out just how good it was going to perform in 4WD conditions. This is also my first 4WD so I was totally inexperienced. Three of us left Adelaide, South Australia for the mid-Flinders Ranges into some of the best unsealed roads and tracks in the country. Although normally semi-arid to desert country, it had recently had some heavy rains. Plenty of really steep washed out muddy tracks into the mountains, lots of creeks to cross, washed out roads exposing deep crevices and rocks, truely a 4WD paradise. Although very hesitant at first, it did not take long to find confidance in the car, I soon learnt to have a lot faith in it. It out performed many other Japanese & Asian vehicles in similar conditions and took my perception of the Discovery as a cross between an off-roader and a soft-roader to being a very capable 4WD. I had second thoughts after buying it, being that Land Cruisers seem to dominate the skyline in this country but I now know it was the best decision I made. And the Flinders Ranges - Spectacular - Awe inspiring.
What kind of mild tweaking was this then? A different chip? Does this=20 improve torque? Would tweaking reduce engine longevity? My neigbour=20 "chipped" his Audi 1.9 TDI, raising torque by some 20%, and was highly=20 enthousiastic about it: said the car drove much smoother (and faster).
I've been thinking about tweaking the Disco (300TDi) this way, but=20 worries about excessive wear and tear held me back. Unlike my neighbour, =
who can't hold on to a car for more then a year, I don't want to part=20 from my beloved Disco. I'm not so much interested in more speed, but in=20 the improved drive and in the extra torque, which, I presume, would come =
in handy when towing our 1400 kg caravan.
Richard
Aust> I can get a hundred=BA on tarmac from a standard 300 TDi
On or around Fri, 10 Oct 2003 14:35:24 +0200, Richard enlightened us thusly:
we-ell...
you start by doing a proper service, including checking the valve clearances and either verifying the EGR thing works correctly or blanking it off, changing all the filters etc.
Then you need to look for smoke. You'll no doubt know how the MOT smoke check is done, viz. floor the throttle, run it up to maximum revs fro a few seconds then lift off. Do this only with the engine fully warmed up. First, see what revs it gets to when you do this. This should be about
4500, and you shouldn't get any serious amount of smoke. A small puff of black smoke on the initial acceleration is OK.
Now to the tweaking - I assume you've not got an EDC one (very late 300 TDi). The first thing is to up the maximum revs a bit - I took it up to
5000. This is not so that you can run it at 5000 revs on the road, there's not much point, but it allows the pump to "open" more at medium revs too. You do this by adjusting the "maximum speed" stop, which is the screw that stops the main pump lever (the one the throttle cable attaches to) at the "open" end. You may need to adjust the throttle cable as well, so you can get the amount of movement you need. Turn the stop screw back a bit at a time, and check what revs you're getting.
Now look again for that smoke. If it's burning very clean, you can afford to turn up the fuelling. On the Bosch pump, the fuelling is adjusted by means of a screw on the back face of the pump, if you envisage the pump looked at from the rear, you have the 4 injector pipe outlets, and a screw which should have a black plastic seal on it which is above these in about the 1 o'clock position. Removing the plastic seal reveals a 13mm A/F locknut, the screw itself has a small (6 or 7mm I think) head on the end of it. To increase the fuelling, you unlock the screw, and turn it in. When unlocking it, make sure the screw stays still, and turn it in by no more than 1/4 turn. The adjustment is quite sensitive, 1/4 turn may be too much. Check for smoke again, if it looks smoky, back the fuelling off a bit.
If you have a tame MOT garage, you could take it for a proper smoke check after playing, to see if it's gonna pass the test :-)
Finally, check the idle speed, as increasing the fuelling can cause that to be a touch high. adjust idle speed according to the book.
usual disclaimers about "if this blow up your engine don't come crying to me". Take it slowly, adjust things a little at a time, and you should come to no harm.
Personally, I've not touched the boost settings - doesn't seem necessary, and the word is that if you up the boost, you need a bigger intercooler as well. Also playing with boost settings without the proper gear is a good way to blow the engine...
Pah! Diesel - Schmeisel! My 3.9 on lpg with a tweak or two puts out 200bhp (rolling road tune) on lpg and showed over 120mph (on the speedo) on the M69 early one morning with no clouds of smoke or regular elastic band replacements for the cam! :)
And what precisely have the good people of Usk ever done to you? ;-)
That tweak certainly does not work. If the governor is calling for more acceleration then that is what it will do. Opening the maximum revs will have absolutely no effect at medium revs. If the accelerator is depressed to accelerate hard then that is what a normal engine will do within the limits of its power and torque.
adjusted by
crying to
should come
necessary,
intercooler as
Boost can be upped slightly to good effect combined with extra fuel. Watch those exhaust gas temperatures though!
Jeremy Fearn mumbled something about doing that to the td5, or making up a small 'orifice' plate to put in the inlet when I was over there. What exactly would this accomplish and how would I go about it ? just blank it off ?
Mine's a '98 Disco with EDC. So I guess, adjustments are out of the question. Thanks for the elaborate explanation. I keep it serviced regularly and drive it at very modest speeds indeed. I get a nasty black smoke on the occasional kick-down. I asked the dealer about this, he drove it, floored it and told me what he saw was normal. In a few weeks the Disco is going to be MOT'd, I'll ask the mechanic to pay special attention to it.
Is there any way to test the EGR (there is no mention of a test in my Haynes)? Or will a malfunction show up as an "check engine"?
|| || Actually, the A40 east of Abergavenny is excellent for the purpose - || 9 miles of lightly-trafficked dual-carriageway with no turnings. ||
Don't fall asleep - there's a roundabout at the end. ISTR a party of pensioners on a coach came to grief there not so long ago. But you're right - it is an awesome stretch of road, and *slightly* downhill, so it flatters the figures a bit.
On or around Sat, 11 Oct 2003 16:53:47 +0100, "Richard Brookman" enlightened us thusly:
The first bit out from abergavenny after you get off the roundabout is dead straight for getting on for a mile... had 109 on the clock in a Renault Clio
1.9 diesel one time.
"We travel not for trafficking alone". 's a quote. Flecker, I think... calls to mind the place I know it from, which is the marvellous (IMHO) book "Mind Over Motor" by W. H. Charnock, who, had there been Land Rovers at the time, would have fitted in with the Land Rover ethos marvellously.
The ending of the book I find particularly poignant...:
Bill Boddy has said that, in his opinion, the day of the large-engined car is about over, and, regretfully, I must agree with him. When 90% of your driving, restricted by the cost of petrol and limited time, consists of short trips over crowded roads and beset with parking problems any other view doesn't make sense. I would go farther and say that I am afraid the day of motoring, as we know and love it, is drawing to a close. I have already outlined the factors that are forcing on us a new concept of utilitarian travel, a concept with which many of us may not wish to be associated.
Other cults, each with its jargon and exclusiveness, will come to replace that which has now outstayed its time. Meanwhile, we have several thousand cherished and individual machines, Rumbold and Behemoth [1] among them, and we have our enthusiasm and our understanding of them and of one another. It may be growing late for them, but there is still time for us to cover collectively many millions of miles before nightfall, an engine ever runs more sweetly in the dusk, and perhaps the bravest motoring of all comes when booming down twilit roads into the sunset. I began this book with a quotation from Flecker and I would like to end it with the same, for it seems to me to be peculiarly apposite. How better to sum up that whole epoch of happy roadfaring in which the car has been a friend and not an instrument, how better for that matter write its epitaph than in those simple words, "We travel not for trafficking alone"?
And while I don't think it's yet come to pass, in the manner which He predicted (I guess that was written in the late 50s, it's definitely post-war) I'm very much afraid that it will... I just hope that by the time we're no longer able or allowed to travel merely for the pleasure of seeing what's around the next corner or over the next hill, in a variety of interesting and to some degree unique vehicles, that I personally will be either dead or past it myself anyway... meanwhile, I'll keep on travelling, as and when finances and time allow, in my inefficient large old motor, and leave the trafficking for another day.
[1] Rumbold was a much-modified open 12/50 Alvis, while Behemoth was an open
4½ Bentley. These, along with a 1940 Jaguar saloon and a Rover 14, were his collection of cars at the time.
On or around Fri, 10 Oct 2003 19:14:45 +0100, "Huw" enlightened us thusly:
If you say so. However, in my estimation it makes a difference. Had some slight trouble getting one through the MOT (it probably needed a new air filter element, I expect) due to a fraction too much smoke. Turning the governor back down to max revs 4500 (this was on a 1.9 citroen) instead of the 5500 that it was set at made it less smoky so that it passed the test with ease, but it felt as flat as a fart by comparison on the road. The effect isn't noticeable at low revs, but at half-revs or more, it definitely makes a difference.
The governor works by balancing some form of inertia against a spring, and this is what determines the fuel throughput. By arranging for the control lever to move further (i.e. upping the max revs) you also allow for more pressure on the spring at medium revs when "fully open", hence more fuel.
If you drive at a medium throttle opening, allow the engine to stabilise, and then open it up slightly, it'll accelerate fairly gently to a new stable speed. If you floor it, it'll accelerate more rapidly.
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