pos
Well-Known Member
I have managed to get just under 89MPH out of my 1986 90 with a retrofitted Discovery 200TDi and I'm certain it'll do a bit more. I have the standard Defender transfer box but I have 235x85xr16 tyres to help with the gearing (they look good too). I noticed that you said you are getting no smoke - is this even when the engine is under load and / or accelerating up hill? The setup that you have sounds fantastic. An over rated intercooler, paired with an increase in boost will make a world of difference but it sounds to me like you may well be starving the engine of the fuel that it needs for any the extra 'oomph'.
Realistically there should be a whisp of black smoke from the exhaust when you deck the pedal to accelerate away from a stand still, or when you accelerate up hill for example. I'd start by doing as was suggested earlier - give the thing a really good service. New engine, gear box, transfer box and axle oils will make a big difference. Also renew the fuel and air filters to ensure that throughput is optimal. I'd also suggest that you remove the intercooler and throughly swill it out with paraffin or thinners until it runs clean. Allow it to dry and then re-fit.
If that doesn't give you the boost that you were looking for, look into your injection pump fuelling. It may well be that someone has had the boost diaphragm out, and it's very easy for it to have been put back in the wrong position - limiting the amount of fuel that your engine receives under boost.
On the very top of your injection pump you will see four flat head bolts securing a metal cover onto the injection pump housing. Remove the four bolts (they should be very very tight) and then you'll be able to see a circular rubber diaphragm. Push the diaphragm up and down whilst rotating it through a whole 360 degrees in either direction - at the same time also trying to pull it up and out of the recess. Eventually, the diaphragm will lift out of it's recess. There should be:
1x boost diaphragm with attached eccentric boost cone
1x coil spring
1x nylon washer
Put these items to one side and then start the engine. If you look down into the recess, you should see a pin which will have shot all the way across the hole. If it hasn't moved, give the engine a quick blip of full throttle and it should shoot across the hole from right to left (or from the front of the engine towards the back of the engine). If you can't see the pin, it's more than likely ceased, which means that the pump isn't delivering any extra fuel for the increase in turbo boost pressure (your lack of power). If however, the pin has moved out across the hole, turn off the engine and then use a small screw driver to push the pin back towards the front of the engine. Once the pin is al the way back in, pick up the boost diaphragm ready for re-assembly.
When you re-fit the boost diaphragm, you want to position it so that the fuel adjustment pin can travel further out into the hole. The eccentric (off set) cone on the boost diaphragm obviously limits the distance that the fuel adjustment pin can travel out into the hole. In this case, the further the better. So examine the cone and decide which position will allow the pin to extend out its furthest. Push the diaphragm back into it's original position, not forgetting the nylon washer or the coil spring and then re-fit the boost diaphragm lid tightly.
Take it for a spin and then let us know how it goes
Of course, if that doesn't fix the problem, you may have a weak or faulty fuel lift pump (not to be confused with your injection pump), a hole in one of your fuel lines or a split /crack in the boost pressure pipe that runs between the turbo compressor housing and the very top of the injection pump. If this pipe is not connected tight at both ends, or if it has a split, the pressure from the turbo will not push the boost diaphragm down, and you'll get no extra fuel.
-Pos
Realistically there should be a whisp of black smoke from the exhaust when you deck the pedal to accelerate away from a stand still, or when you accelerate up hill for example. I'd start by doing as was suggested earlier - give the thing a really good service. New engine, gear box, transfer box and axle oils will make a big difference. Also renew the fuel and air filters to ensure that throughput is optimal. I'd also suggest that you remove the intercooler and throughly swill it out with paraffin or thinners until it runs clean. Allow it to dry and then re-fit.
If that doesn't give you the boost that you were looking for, look into your injection pump fuelling. It may well be that someone has had the boost diaphragm out, and it's very easy for it to have been put back in the wrong position - limiting the amount of fuel that your engine receives under boost.
On the very top of your injection pump you will see four flat head bolts securing a metal cover onto the injection pump housing. Remove the four bolts (they should be very very tight) and then you'll be able to see a circular rubber diaphragm. Push the diaphragm up and down whilst rotating it through a whole 360 degrees in either direction - at the same time also trying to pull it up and out of the recess. Eventually, the diaphragm will lift out of it's recess. There should be:
1x boost diaphragm with attached eccentric boost cone
1x coil spring
1x nylon washer
Put these items to one side and then start the engine. If you look down into the recess, you should see a pin which will have shot all the way across the hole. If it hasn't moved, give the engine a quick blip of full throttle and it should shoot across the hole from right to left (or from the front of the engine towards the back of the engine). If you can't see the pin, it's more than likely ceased, which means that the pump isn't delivering any extra fuel for the increase in turbo boost pressure (your lack of power). If however, the pin has moved out across the hole, turn off the engine and then use a small screw driver to push the pin back towards the front of the engine. Once the pin is al the way back in, pick up the boost diaphragm ready for re-assembly.
When you re-fit the boost diaphragm, you want to position it so that the fuel adjustment pin can travel further out into the hole. The eccentric (off set) cone on the boost diaphragm obviously limits the distance that the fuel adjustment pin can travel out into the hole. In this case, the further the better. So examine the cone and decide which position will allow the pin to extend out its furthest. Push the diaphragm back into it's original position, not forgetting the nylon washer or the coil spring and then re-fit the boost diaphragm lid tightly.
Take it for a spin and then let us know how it goes
Of course, if that doesn't fix the problem, you may have a weak or faulty fuel lift pump (not to be confused with your injection pump), a hole in one of your fuel lines or a split /crack in the boost pressure pipe that runs between the turbo compressor housing and the very top of the injection pump. If this pipe is not connected tight at both ends, or if it has a split, the pressure from the turbo will not push the boost diaphragm down, and you'll get no extra fuel.
-Pos
Grippa
New Member
I have managed to get just under 89MPH out of my 1986 90 with a retrofitted Discovery 200TDi and I'm certain it'll do a bit more. I have the standard Defender transfer box but I have 235x85xr16 tyres to help with the gearing (they look good too). I noticed that you said you are getting no smoke - is this even when the engine is under load and / or accelerating up hill? The setup that you have sounds fantastic. An over rated intercooler, paired with an increase in boost will make a world of difference but it sounds to me like you may well be starving the engine of the fuel that it needs for any the extra 'oomph'.
Realistically there should be a whisp of black smoke from the exhaust when you deck the pedal to accelerate away from a stand still, or when you accelerate up hill for example. I'd start by doing as was suggested earlier - give the thing a really good service. New engine, gear box, transfer box and axle oils will make a big difference. Also renew the fuel and air filters to ensure that throughput is optimal. I'd also suggest that you remove the intercooler and throughly swill it out with paraffin or thinners until it runs clean. Allow it to dry and then re-fit.
If that doesn't give you the boost that you were looking for, look into your injection pump fuelling. It may well be that someone has had the boost diaphragm out, and it's very easy for it to have been put back in the wrong position - limiting the amount of fuel that your engine receives under boost.
On the very top of your injection pump you will see four flat head bolts securing a metal cover onto the injection pump housing. Remove the four bolts (they should be very very tight) and then you'll be able to see a circular rubber diaphragm. Push the diaphragm up and down whilst rotating it through a whole 360 degrees in either direction - at the same time also trying to pull it up and out of the recess. Eventually, the diaphragm will lift out of it's recess. There should be:
1x boost diaphragm with attached eccentric boost cone
1x coil spring
1x nylon washer
Put these items to one side and then start the engine. If you look down into the recess, you should see a pin which will have shot all the way across the hole. If it hasn't moved, give the engine a quick blip of full throttle and it should shoot across the hole from right to left (or from the front of the engine towards the back of the engine). If you can't see the pin, it's more than likely ceased, which means that the pump isn't delivering any extra fuel for the increase in turbo boost pressure (your lack of power). If however, the pin has moved out across the hole, turn off the engine and then use a small screw driver to push the pin back towards the front of the engine. Once the pin is al the way back in, pick up the boost diaphragm ready for re-assembly.
When you re-fit the boost diaphragm, you want to position it so that the fuel adjustment pin can travel further out into the hole. The eccentric (off set) cone on the boost diaphragm obviously limits the distance that the fuel adjustment pin can travel out into the hole. In this case, the further the better. So examine the cone and decide which position will allow the pin to extend out its furthest. Push the diaphragm back into it's original position, not forgetting the nylon washer or the coil spring and then re-fit the boost diaphragm lid tightly.
Take it for a spin and then let us know how it goes
Of course, if that doesn't fix the problem, you may have a weak or faulty fuel lift pump (not to be confused with your injection pump), a hole in one of your fuel lines or a split /crack in the boost pressure pipe that runs between the turbo compressor housing and the very top of the injection pump. If this pipe is not connected tight at both ends, or if it has a split, the pressure from the turbo will not push the boost diaphragm down, and you'll get no extra fuel.
-Pos
Just how fast it goes woulda dun!
pos
Well-Known Member
Thanks a lot
As for the bit of black smoke - it does it. When i go up the hill on full throtle - it does the small black puff from time to time - also when accelerating rapidly - same thing. So it cant be this. Air filter - well, as long as turbo gauge works, and shows the correct pressure - it means that engine has all the air it needs (however it may be only because of turbo going at higher rate to fight stuffed filter - i'll try it without one tomorrow) It does about 28-30mpg - so seems pretty usual too. Fuel filter - recently changed. As for the injector pump - as im not much of a clocksmith, wouldn't like to mess with it, unless there is no other option left. As for good service: spent about 3grand recently on it. fully recon gearbox transferbox, all fluids (inc axles), and much more irrelevant to the bhp.
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wanderlust4ever
Active Member
Like **** Of A Stick
jamescronin
Active Member
Two other things to check out:- check your transfer box to make sure sombody has not replaced it with a range rover or some other box with a stupid ratio in it - should be 1:1.4 if its a defender one.
Other thing to check is to remove the intercooler, and flush it out as if its full of muck then you will still get a dencent pressure in the wastegate pipe (I presume this is where your boost guage is attached to?) but the air will not have been colled, hence reducing the power outout of the engine.
I suspect your engine may be fine, but something stupid is causing it to not reach top power output/put this power onto the road correctly.
Other thing to check is to remove the intercooler, and flush it out as if its full of muck then you will still get a dencent pressure in the wastegate pipe (I presume this is where your boost guage is attached to?) but the air will not have been colled, hence reducing the power outout of the engine.
I suspect your engine may be fine, but something stupid is causing it to not reach top power output/put this power onto the road correctly.
pos
Well-Known Member
That's what I'm hoping for his sake! A very quick way to check that your engine isn't goosed (i.e. worn piston rings or worn bores for example) is to take it to your local garage for a leakage test. This will show you the efficiency of each cylinder as a percentage. 100% Is obviously as good as it can get, and anything under 90% needs attention in order to restore lost power. It might be worth having a leakage test done before you spend more money on other bits and bobs!
-Pos
Absolutely vital that I spend most of my time driving at 74 mph- it's over 70mph and therefore really noisy so it drowns out all the noise of the kids in the back so I can delude myself into thinking Im childless......
and its under 75 mph after which I need to have an arm transplant to cope with the strong wobble that starts to occur
and its under 75 mph after which I need to have an arm transplant to cope with the strong wobble that starts to occur
pos
Well-Known Member
Absolutely vital that I spend most of my time driving at 74 mph- it's over 70mph and therefore really noisy so it drowns out all the noise of the kids in the back so I can delude myself into thinking Im childless......
and its under 75 mph after which I need to have an arm transplant to cope with the strong wobble that starts to occur
Plus at 74, a speed camera wont get you.
tombardier
Well-Known Member
try seeing if the throttle pedal is adjusted to allow the throttle to fully open
MrJC
Well-Known Member
I was looking through my Haynes Manual for something else when I saw 'Engine lacks power' in the Fault Finding section. Most has been covered above but a brief summary is:- Air in fuel, Incorrect fuel injection pump timing, Timing chain/belt incorrectly fitted or tensioned, fuel filter choked, uneven or low cylinder compessions, brakes binding , clutch slipping (sure you would have noticed)
Oh well.... back to how to replace steering fluid
, clutch slipping (sure you would have noticed)Oh well.... back to how to replace steering fluid
123-eddy09
Active Member
Got 75 out of my standard 300tdi but that was on the flat. I reckon it will do about 80-85 down a good hill.
