Disco 2 Lacking in performance and acceleration

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The MAP was gunked up exactly due to the EGR so blanking it will keep it cleaner and provide a better air flow, as about the flat spot it needs investigation with scanner on live data i dont like guessing games

however, this
Simon Perks said:
Im also still not convinced that my village garage put enough transmission fluid in at service as I gave him 10 liters but got 6 back..
Click to expand...
is not OK especially if the oil was old in the box, then after a change which allows 4-5 l of oil to be renewed you should drive the vehicle few miles as to change several times through all the gears then renew the oil again and a new filter, there are 9.7 litres of oil in that box but more than half remains trapped in it when you release the drain plug if you see what i mean so changing it twice will renew about 85% of it and the procedure with changing through all the gears at idle after it was filled is compulsory too as described in the workshop manual
 
I'm reading this thread with great attention as I too have a problem like this.
Mine occurs mostly when the engine is hot. Flat spot occurs when I have to come to a halt e.g. at traffic lights.
I go to move off and even with my accelerator planted flat on the floor the engine only revs up after quite a while.
Once moving it drives as normal.
I too have just cleaned all sensors and even disconnected the MAF.
I do have the EGR deleted and the MAP/IAT was nowhere near as dirty as I would have expected it to be. In fact almost no dirt came out of it.
Simon we have both said about the gearbox oil change now. I know it's a pain in the bum, but the easiest way to do it is with a garden pressure sprayer like you use for weedkiller. You can pump it up and get pressure in it before you need to use it Then once you have run it through the gears and got the filler plug out, you can just trigger the sprayer and stop when the ATF runs out.
I am wondering if any of my inlet pipes are delaminated but if they were, why would the problem be worse when the engine is hot?
Hope you don't think i am hijacking your thread.
 
Stanleysteamer said:
I'm reading this thread with great attention as I too have a problem like this.
Mine occurs mostly when the engine is hot. Flat spot occurs when I have to come to a halt e.g. at traffic lights.
I go to move off and even with my accelerator planted flat on the floor the engine only revs up after quite a while.
Once moving it drives as normal.
I too have just cleaned all sensors and even disconnected the MAF.
I do have the EGR deleted and the MAP/IAT was nowhere near as dirty as I would have expected it to be. In fact almost no dirt came out of it.
Simon we have both said about the gearbox oil change now. I know it's a pain in the bum, but the easiest way to do it is with a garden pressure sprayer like you use for weedkiller. You can pump it up and get pressure in it before you need to use it Then once you have run it through the gears and got the filler plug out, you can just trigger the sprayer and stop when the ATF runs out.
I am wondering if any of my inlet pipes are delaminated but if they were, why would the problem be worse when the engine is hot?
Hope you don't think i am hijacking your thread.
Click to expand...

Not in the slightest Stanley feel free mate.
Actually i did the garden sprayer trick at the weekend and got another couple of liters in there but it's a hell of a mess.
I'm going to go by and ask the village garage if they can read off the codes for me just see if there's a clue there.
What I do notice is that mine just loves to tow a trailer, it seems much happier pulling a weight as it had done all it's life before i had it.. could this have something to do with it being run in at an early age like that?
Lie you say.. when its going its fine on the motorway and i have to keep reminding myself it's not the V8 and i'm not in a racing car.

Simon
 
Stanleysteamer said:
I'm reading this thread with great attention as I too have a problem like this.
.
Click to expand...
Stanley,
have tried cleaning the crank sensor?
So i found the plug on the fuel thingy (under the manifold) was loose and full of oil, cleaned that.
Took out the crank sensor (the one on the bell housing) also dirty, cleaned that.
Next drive is in the morning to work, ill report back if its made any difference.

Simon
 
Simon Perks said:
Stanley,
have tried cleaning the crank sensor?
So i found the plug on the fuel thingy (under the manifold) was loose and full of oil, cleaned that.
Took out the crank sensor (the one on the bell housing) also dirty, cleaned that.
Next drive is in the morning to work, ill report back if its made any difference.

Simon
Click to expand...
No i have done neither. If you can come up with some pics as to locations I'd be very grateful.
Looking forward to hearing how you get on.:):):)
 
Stanleysteamer said:
No i have done neither. If you can come up with some pics as to locations I'd be very grateful.
Looking forward to hearing how you get on.:):):)
Click to expand...

Stanley,
Ok so it made a difference but didn't fix the issue
Made the tick over stable and the acceleration feels better but only up to a point and here's the weird thing.
Accelerating with the pedal we have the flat spot bit where even foot to floor doesn't seem to bring anything however on the dual carriageway this morning using the cruise control it did.
I set the control whilst doing 80kmh and then used the +button and it pulled no problem like really accelerated up to the allowed 120kmh.
this brings me back to that throttle potentiometer on the pedal .. i would say
@sierrafery expert sir what would you deduce, i'm still going to have the ATF changed again before my UK trip in october.

Simon
 
Simon Perks said:
...this brings me back to that throttle potentiometer on the pedal .. i would say.
@sierrafery expert sir what would you deduce,
Click to expand...

Hi, as i said i can't deduce much without a live data log, the management responds different to TPS and CC acceleration, usually a TPS fault gives different symptoms and brings on the engine malfunction warning... if you can't find somebody with nanocom to record fuelling inputs then replace the pedal with a known good one to rule it out of your mind but for me is not very suspect yet...seems more like a lack of boost or fuelling issue to me which is just a guess without live readings cos the stall test is at the lower limit too, with good power it would be closer to 2800 rpm
 
sierrafery said:
Hi, as i said i can't deduce much without a live data log, the management responds different to TPS and CC acceleration, usually a TPS fault gives different symptoms and brings on the engine malfunction warning... if you can't find somebody with nanocom to record fuelling inputs then replace the pedal with a known good one to rule it out of your mind but for me is not very suspect yet...seems more like a lack of boost or fuelling issue to me which is just a guess without live readings cos the stall test is at the lower limit too, with good power it would be closer to 2800 rpm
Click to expand...

Good point, now i have cleaned up I will do the stall test again this evening on the way home.
So boost would be turbo issue? and fueling? could this be something i disturbed when i did the head gasket?
 
Low boost can be caused by many reasons: sticking wastegate, delaminated or leaking hoses, clogged or leaking intercooler, low air flow from the inlet, etc, also it can be a management issue or low fuel pressure... the fact that you cleaned the MAP sensor which has a huge involvment in fuelling and boost management doesnt mean that the sensor is reading well and the calculation is made in conjunction with the airbox sensor too also important... or if it's Eu3 the MAF is very important, actually so are all the sensors... these things can be ruled out only with diagnostic tool on live data...unless there is a fault code logged too

did you set the injector clearances as in the book after the HG replacement?
 
[QUOTE="sierrafery, post: 5420585, member: 9153 did you set the injector clearances as in the book after the HG replacement?[/QUOTE]
Err yes the wind it all the way down and a half turn back .. was it ? something like that .. you mean the things that are like the tappets on my S3?
 
Simon Perks said:
wind it all the way down and a half turn back
Click to expand...
I know nothing about the S3, on the Td5 it must be a full turn back when the plunger is at full stroke on each injector, from the WSM(which should be your guide if you DIY):
turn back the adjusting screws then:
...
7. Rotate engine clockwise until No 1 injector lobe
is at full lift.(plunger fully down)
8. Rotate rocker adjusting screw clockwise until
the injector plunger is felt to bottom out.
9. Rotate rocker adjusting screw anti-clockwise
one complete turn to give plunger the required
bump clearance and tighten rocker arm
adjusting screw locknut to 16 Nm (12 lbf.ft) .
CAUTION: Ensure screw does not turn as
locknut is tightened.
10. Carry out above procedure for the remaining 4
rocker arms.
11. After completion of rocker arm adjustment,
slowly rotate engine clockwise 2 complete
turns by hand to ensure that no injectors are
bottoming out on their plungers
 
sierrafery said:
I know nothing about the S3, on the Td5 it must be a full turn back when the plunger is at full stroke on each injector, from the WSM(which should be your guide if you DIY):
turn back the adjusting screws then:
...
7. Rotate engine clockwise until No 1 injector lobe
is at full lift.(plunger fully down)
8. Rotate rocker adjusting screw clockwise until
the injector plunger is felt to bottom out.
9. Rotate rocker adjusting screw anti-clockwise
one complete turn to give plunger the required
bump clearance and tighten rocker arm
adjusting screw locknut to 16 Nm (12 lbf.ft) .
CAUTION: Ensure screw does not turn as
locknut is tightened.
10. Carry out above procedure for the remaining 4
rocker arms.
11. After completion of rocker arm adjustment,
slowly rotate engine clockwise 2 complete
turns by hand to ensure that no injectors are
bottoming out on their plungers
Click to expand...

WSM?
 
sierrafery said:
I know nothing about the S3, on the Td5 it must be a full turn back when the plunger is at full stroke on each injector, from the WSM(which should be your guide if you DIY):
turn back the adjusting screws then:
...
7. Rotate engine clockwise until No 1 injector lobe
is at full lift.(plunger fully down)
8. Rotate rocker adjusting screw clockwise until
the injector plunger is felt to bottom out.
9. Rotate rocker adjusting screw anti-clockwise
one complete turn to give plunger the required
bump clearance and tighten rocker arm
adjusting screw locknut to 16 Nm (12 lbf.ft) .
CAUTION: Ensure screw does not turn as
locknut is tightened.
10. Carry out above procedure for the remaining 4
rocker arms.
11. After completion of rocker arm adjustment,
slowly rotate engine clockwise 2 complete
turns by hand to ensure that no injectors are
bottoming out on their plungers
Click to expand...

Thanks mate your a star awesome, I'm going to revisit this as the term "bottom out" wasn't really as far as whent last time, i just screwed the screw down until it touched the top of the plunger but if I understand you correctly it's got to be pushing the plunger like properly down.
 
sierrafery said:
yes, the plunger must reach the bottom of the nozzle then back one turn ... go back two pics from the end of this thread http://www.discovery2.co.uk/Injector Seals.html
Click to expand...

Ok I checked this when I got home, most of them I had to turn 3 or more turns of the screwdriver further down from where they were, only took it for the short drive to the garage for tomorrow’s tyre change but it climbed the hill with ease so I’m hoping it’s a significant improvement, Thursday evening I have a 200km so I’ll find out then.

also ordered an OBD reader ( Bluetooth plug in with an app)

fingers crossed

simon
 
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