Td5 losing puff or is it me?

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109inches

Well-Known Member
Posts
644
Location
Devon
I've been reading a lot of posts the last few days about td5 discoverys and how they perform on hills. Nothing really gives a solid answer I just want to know if my td5 is producing less power than it should be. It's a 1999 es discovery all standard, with new vdo MAF, egr blanked off and MAP all cleaned. No turbos pipes are split, the wastegate moves freely with some mole grips attached and no brakes are sticking, it's a 5 speed manual.

On the flat the power is adequate in fact it pulls pretty damn well and I previously owned a powerful diesel saloon and this disco doesn't feel bad on the flat. However hills are another matter, it's incredibly slow to pick up when changing down a gear on long stretches of hills or turning onto a hill at slow speed to the point pressing the pedal does nothing until it's caught its breath at about 2000rpm.

Then on a particular hill on a stretch of dual carriageway I will enter the base of the hill at 70mph in 5th with my foot planted, and after about 80 metres at the end of the hill my speed has reduced to 45mph. The hill is about a 15-20 degree angle. Now idk if this is right I'm assuming not because it seems like it would never get up a hill with a trailer on the back. I'm ordering a hawkeye to see if any faults are logged, but it seems to dislike hills as much as my 2.25 diesel series 2.
 
I think I would try a temp boost gauge to see whats going on, Ive had a MAP sensor slowly fail causing loss of power.
 
lynall said:
I think I would try a temp boost gauge to see whats going on, Ive had a MAP sensor slowly fail causing loss of power.
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Thanks for the reply lynall I've tried disconnecting it and can feel a big difference with it disconnected the td5 becomes a non turbo. My only other thought is fuel pump however I have tested driving in fourth on the flat and it pulls strongly to 70mph which is 3000rpm and feels like it will keep going. Get to a hill and the engine revs slowly decrease. You can change down to fourth and it still won't accelerate or even maintain road speed.
 
neilly said:
Can you feel the turbo coming on song at 1800RPM?

Cheers
Click to expand...
Yeah it pulls nicely and when on the flat gets stronger and stronger in higher gears especially 5th the vehicle feels a little flat even over 2000rpm, but on hills it doesn't matter where in the rev range you are it will not accelerate or even hold the power. Through 1st to the lower rev range of fourth it pulls nice and strongly on the flat in fifth not so much it probably takes 8 seconds to get from 60-70mph on the flat and joining from slip roads isn't much fun in it.

Shimsteriom said:
What do you mean? When my MAF was playing up, the turbo still spun up and produced boost when it was disconnected.
Click to expand...

The turbo works but with the MAP sensor disconnected it felt like there was no turbo at all. Pulling in 3rd was like pulling in 5th.
 
109inches said:
Yeah it pulls nicely and when on the flat gets stronger and stronger in higher gears especially 5th the vehicle feels a little flat even over 2000rpm, but on hills it doesn't matter where in the rev range you are it will not accelerate or even hold the power. Through 1st to the lower rev range of fourth it pulls nice and strongly on the flat in fifth not so much it probably takes 8 seconds to get from 60-70mph on the flat and joining from slip roads isn't much fun in it.
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This smacks of exactly the same issue I used to have until I put a new MAF (not MAP ;) ) on it.
 
109inches said:
It has a brand new maf on it made by vdo. It's a possibility it could be faulty but I have no way of testing it accurately enough at the minute
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Mine was a new VDO as well, and it would appear that it's broke, after just 12 months. Just because something is brand new, doesn't mean it works. :)
Worth a go. Do you know anyone else with a D2 without any issues that would let you swap the MAFs for a run?
 
I don't have access to another known good maf. As I say I have a hawkeye on order. It's something I've been meaning to get for a while as I plan on using this discovery until it dies or I can't afford to fix it anymore and even then I might buy another. I might unplug it again and try the hill in as close to identical conditions. I know it will cause underfueling slightly but I would've thought the default setting would be better than the poor reading I'm getting if it is that.

Also is it recorded that the maf wires are known to break or rub through? Just thinking of anything to check related to fuelling and air.
 
when my fuel pump started to go I lost power going up hills and it got progresively worse I started to find it was okay up to about 50mph then would not go any faster, I also lost power on hills when I had a problem with fuel pressure regulator, I do not know how fast you normally drive but if you could find some-where where you could try it flat-out on the flat a see if as it needs more fuel it stops going faster if this is the case it would most likely be a lack of fuel, when my pump was not working the faults that where shown where injector problems, I think this was because they where not getting all the diesel they needed
 
It's always been like it. But never really noticed until I drove it around where I live because it was all motorway on the way home. I've had it since February and it always seemed flat. Disconnected the maf and it felt better so ordered a vdo one and to be honest I was expecting the performance to improve further and it stayed the same as when disconnected. After that a full service was done every filter replaced with genuine or quality part, all drivetrain oils, all intercooler hoses inspected but I don't get any noises that sound like a boost leak, turbo looks in pretty good condition for 155,000 miles, map sensor was removed and cleaned with brake cleaner after I removed the egr. I've triple checked every connection and jubilee clip in case I've missed anything. The brakes aren't dragging at all the tyre pressure are all correct. It comes down to replacement maf is crap, MAP sensor underreading or maybe the wastegate modulator thing. Which by the state of it could be an original. So might be worth by passing or changing to see what happens.
 
Ian M in France said:
when my fuel pump started to go I lost power going up hills and it got progresively worse I started to find it was okay up to about 50mph then would not go any faster, I also lost power on hills when I had a problem with fuel pressure regulator, I do not know how fast you normally drive but if you could find some-where where you could try it flat-out on the flat a see if as it needs more fuel it stops going faster if this is the case it would most likely be a lack of fuel, when my pump was not working the faults that where shown where injector problems, I think this was because they where not getting all the diesel they needed
Click to expand...

I have managed to get it to 90mph in fifth to test just this. Wrong I know but it felt like it wanted to keep going it took time getting there but the engine wasn't kangarooing, or spluttering or showing any symptoms of lack of fuel.
neilly said:
Just for info , how many threads are showing on the wastegate actuator bar?

Cheers
Click to expand...
From memory I couldn't tell you probably about an inch and half of thread showing beforing the lock off nut.
 
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