gutless disco

[thumbs]

i think my 300tdi disco feels sluggish, and in my opinion getting worse

had a trailor on it yesterday (about 1.5 ton) and was struggling to maintain 50, had to hold it in forth wouldnt even cruise on the flats in 5th just slowed down.

pulling awy normal driving is slow going till boost kicks in, and it seems to loose boost quickly and the slightest incline really holds it back,

is this normal? any ideas?

checked all turbo hoses, they look ok, although not the best light to look properly. jsut had service with all the filters.

my mates got a 300tdi 90 anfd that seems alot better on the road, in no they have a lower geared transfer box but it is a vastly noticeable difference.

any help much appreciated

[landyman Ash]

My 300tdi with 2.5 ton on will do 50 no probs (although not much more)

Without driving it I could not tell you nothing mate

Have a looked at your regional meet?  Someone will tell you stright away if its wrong

[Porny]

It could be a number of things....

Check all the intercooler hoses:
Delaminating could be one problem, but check for splits etc.
Sounds like the turbo is 'boosting' so air may not be getting to the intake manifold due to a leak.

Fuelling (lift pump):
Unscrew the fuel filter and see if it is filled to the brim (engine off)
If not, it is a sign that your lift pump is not pumping the required amount of fuel... i.e. that it's gone weak.

Injector pump:
You may have a split diagram in the top of the injector pump or it has been set to the wrong position
To check this, (with engine off) remove the four screws from the anode on the top of the injector pump (see pic)
Mark the position of the diagram with a marker pen so that you can put it back in the same place, and then remove it by gently pulling upwards and check for splits.

If it is ok, then.... it may be at its minimum setting.

The diaphragm and cone controls the ratio between boost pressure and associated fuel delivered. A small pin (which controls fuel) slides against the side of the cone. As the diaphragm is pushed down, the pin slides inwards against slope of the cone and so more fuel gets delivered.

As you look at the profile of the cone, it has different slopes depending on which angle faces the pin. So depending on its rotation, you can set which slope faces the pin, and so which ratio of fuel to boost pressure is delivered.

Its max setting is the one that would cause the pin to move the most. I.e. so that the largest is facing towards the front of the engine (see pics). It's up to whether to set it to max or not, but I put it somewhere close ish (say 45 degrees from max). If the diagram has been assembled correctly there will be a dimple of the metal plate which should face towards the rad on the max setting.
See pic/drawing - sorry it's a bit naff!!!

Throttle Cable
Another favorite... check the accelerator cable is adjusted correctly, as they have a habit of stretching or backing themselves off.
With the engine off, get someone to press the accelerator pedal to the floor, and check the lever on the injector pump gets to the 'maximum' stop, if not adjust as needed.

Boost Pipe:
Check the pipe that runs from the actuator on the turbo to the anode on the injector pump - it may be that this split or blocked (disconnect and blow through with an airline)

Boost pressure of the Turbo:
Connect a Boost Gauge and go for a drive - try and find a longish hill and attack it flat out in 4th (or 3rd) and see what the maximum pressure is. It should be 1 bar or 15 psi (just over a bar which is 14.7psi) - if lower then adjust to suit. (1bar on a 300Tdi, 0.8 bar on a 200Tdi - though you can run 1 bar without a problem on a 200Tdi)

Engine Timing:
Does the engine struggle to start?? Or smoke when running.
When the cam belt was replaced they may have incorrectly set the engine timing.
To check....(engine off)

If you look on the front cover on the engine, you will see an inspection plate attached by three screws, remove this and you will see the pulley that drives the fuel injection pump.
If you look at this, you should see a timing hole. Turn the engine over with a bar (with a socket on the damper bolt) until this timing hole lines up with the timing hole in the timing cover behind the pulley (use of a torch helps) - when it does insert an 8mm or 10mm drill bit (plain end first) - if you gently try turning the engine over now, it should be locked.

Once this is locked, go underneath the Land Rover (with a torch) and look up through the hole in the flywheel housing at the flywheel. If the timing is correct you should see a cut out in the flywheel. If it not there, try just turning the engine slightly either way with the bar (still with fuel pump locked) and look to see if you can see it. If the timing is correct it will be there.
If not.... remove the drill bit from the fuel injector pump and get somebody to turn the engine over with the bar until you can see it, to see how far out/and what your looking for.

Read this guide for some pics etc:
http://www.difflock.com/servicing/30...lt/index.shtml

Intercooler:
Get it leak checked or do it your self.
Easiest way is to bung one end, and pressurise the other (ideally between 1.5bar and 2bar) and then submerge in a tank of water - then look for bubbles.

Inlet Manifold:
Make sure the gasket is ok and not leaking.

Fuel Lines:
Check all the fuel lines for split, cracks, kinks etc etc.
Especially those on the feed side.

Fuel Cap:
Remove this when the engine is running (or just after) do you get a hiss of air??? - if so, fuel tank vent or vented cap may be blocked.



Ian

[Porny]

Just a side note:

My 110 200Tdi on the flat will (on a private road) sit at 70mph even with 1.5 ton of trailer on the back... will go quicker still if required, on hills it doesn't drop below 60mph.

My parents Disco will do the same.


Ian

[Budgie]

Don't just look on the outside of the intercooler hoses, they can de-laminate on the inside blocking the airflow into the engine.

Are you sure the turbo is cutting in? Only it sounds like mine when the boost leaver to the turbo can away from the wastegate. (The C-clip fell off!) This is located under where the EGR valve is on the exhaust minfold.

Also check the black tube from the top of the injector pump to the turbo for leaks as this will stop extra fuel getting to the engine and slow you up.

[Budgie]

Looks like you were posting that lot while I was typing mine the Porny!!  :D

[Porny]

Have you got EGR on your Disco?


Ian

[Porny]

Looks like you were posting that lot while I was typing mine the Porny!!

I cheated... had posted this on another forum a while ago  


Ian

[POTASH]

check if your fuel lift pumps working ok

[thumbs]

thanks for your help everyone, will work my way down the list.

ill take every hose of and inspect properly, was going to alter pump anyway, will check intercooler and lift pump, and everything else,

yes it has got egr but that will be comeing off as ive got the bits to do it.

cheers, ill let you no how i get on

[thumbs]

ALL SORTED

its like driveing a different motor, found in the end a little pipe that goes from the turbo round the back of block and connects to pump was off, most have been working loose for a while.

reffited that with new banjo bolt, checked all hoses ok, removed egr valve, and tweeked pump 90deg.

all i can say is wow, it pulls away  :D

[Richie_EB4]

Boost pressure of the Turbo:
Connect a Boost Gauge and go for a drive - try and find a longish hill and attack it flat out in 4th (or 3rd) and see what the maximum pressure is. It should be 1 bar or 15 psi (just over a bar which is 14.7psi) - if lower then adjust to suit. (1bar on a 300Tdi, 0.8 bar on a 200Tdi - though you can run 1 bar without a problem on a 200Tdi)

Any one tell me where and how to fit a boost gauge please

[Sharpshooter]

Can anyone tell me How much the fuel consumption is affected by tweeking the pump, as shown above please??

Also, my 200Tdi disco, will do 60mph easy with my 3500kg ifor on the back.(not fully loaded) Drops down to 50 ish on good hills.

[Budgie]

IIRC my Disco went from about 30 mpg down to around 26-28 mph, depending on how I drove it.

It's down to around 23 mpg now the tyres have got bigger and the transfer box has been changed.  :?

[Porny]

Any one tell me where and how to fit a boost gauge please

Very easily....

The easiest way to connect a boost gauge is between the turbo compressor housing and the actuator... if you look in the Land Rover workshop manuals, this is the method they also suggest.

You could also put a tapping into the inlet manifold, which would show 'true' pressure, but in all honesty just tapping into the actuator feed is more than enough for most people.

I have attached some pictures of my boost gauge fitted to my 90... which although a slightly different set-up to a Disco, uses the same principle.

Just bear in mind that not all boost gauges are calibrated correctly, and the reading should only be use 'as indication only'... if any body does want to check the accuracy of their boost gauge just drop me a pm.

Can anyone tell me How much the fuel consumption is affected by tweaking the pump, as shown above please??

How long is a piece of string???

Fuel consumption above everything else comes down to you right foot.

With my injector pump tweaked, my fuel consumption hasn’t changed... unless I take advantage of the extra performance.

On average, I get about 26mpg... which is a mixture of towing, motorway work (my 110 will happily do 80 - 85mph) and general A roads.

Heavy towing or prolonged use of a heavy right foot sees this drop to anywhere down to 20mpg... but not that often.

In all honesty, not much worse than before... and possibly slightly better when driven economically!!!


This is from a 110" 200Tdi CSW.


At the end of the day, the pump mods are simply a mechanical adjustment and can be changed back... so a case of suck it and see...

Also, my 200Tdi disco, will do 60mph easy with my 3500kg ifor on the back.(not fully loaded) Drops down to 50 ish on good hills.

On a private road....

My 110 will happily pull nearly 80mph with just over a car tonne of trailer on the back.... with 2 tonne on the back it will still pull 70mph easily on the flat, and drops to 60mph - at worst 50mph without a run up.

My 110" has usual pump mods, and runs 1 bar boost pressure.


Ian