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amondeggs



Member Since: 06 Mar 2011
Location: Telford
Posts: 452

United Kingdom 1999 Defender 90 Td5 HT Woodcote Green
wslr wrote:
Your MAF may be maxing out and then putting the ECU into a default setting. You can watch it on Testbook. MAF will jump up past 640kgpa and then it goes off the scale at which point the ECU presumes the MAF has a problem and starts running a basic default. That's the point at which the lack of power starts, and when you back off the power, the ECU sees a good reading again and everything appears normal.

Ask Gary for an uprated MAF sensor.


That does make sense Thumbs Up

What is testbook ? Is it a diagnostics system? It goes without saying I don't have one of these .

I will contact Gary re uprated mass air flow sensor , I guess these are not cheep Question

Thanks for the suggestion Thumbs Up
Post #132234 18th Mar 2012 7:43am
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party monkey



Member Since: 31 Dec 2010
Location: Oxon.
Posts: 1311

England 2005 Defender 110 Td5 XS CSW Cairns Blue
Gary put a new genuine (Siemens/VDO I think) MAF on mine last April as part of my remap. Back then it was £75+VAT for the MAF to give you a guide.

Is there such a thing as an 'uprated' MAF? I just thought you either bought genuine LR or cheaper copy.

Think Testbook is LR's own diagnostic system that main dealers/Indy's use.

If you have a mate locally with say a Td5 unlocked Nanocom, I guess you should be able to get the live readings off that.

I'll be taking a delivery of one in the next week or so and you're more than welcome to pop along and plug her in and see what readings you get. Only prob is that I'm in Buckingham area and no real plans to head your way in the near future. Jon - 110 td5 [sold]. Currently Defenderless.
Post #132253 18th Mar 2012 9:00am
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amondeggs



Member Since: 06 Mar 2011
Location: Telford
Posts: 452

United Kingdom 1999 Defender 90 Td5 HT Woodcote Green
party monkey wrote:
Gary put a new genuine (Siemens/VDO I think) MAF on mine last April as part of my remap. Back then it was £75+VAT for the MAF to give you a guide.

Is there such a thing as an 'uprated' MAF? I just thought you either bought genuine LR or cheaper copy.

Think Testbook is LR's own diagnostic system that main dealers/Indy's use.

If you have a mate locally with say a Td5 unlocked Nanocom, I guess you should be able to get the live readings off that.

I'll be taking a delivery of one in the next week or so and you're more than welcome to pop along and plug her in and see what readings you get. Only prob is that I'm in Buckingham area and no real plans to head your way in the near future.


Ok thanks for the info and for the offer of plugging in with nanocom. I wish I were closer I would take you up on that Thumbs Up

I don't know if the maf is original or not? Is there a part number I should look for Question
Post #132261 18th Mar 2012 9:14am
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wslr



Member Since: 18 Jul 2010
Location: Wellington, Somerset
Posts: 581

United Kingdom 
No, Gary's are a modified unit, so even a brand new Genuine Part or VDO will do the same thing as the existing one.

Best call Ben or Gary at Alive and get one on order.

Who did the original map, and has the vehicle always had this issue?
Post #132305 18th Mar 2012 2:10pm
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amondeggs



Member Since: 06 Mar 2011
Location: Telford
Posts: 452

United Kingdom 1999 Defender 90 Td5 HT Woodcote Green
I am not sure who did the map as it was done when I bought the car. I will try and find out though.

The has not always done this only in the last few times out. As I previously mentioned I had an engine management light down at Salisbury and had to get towed home Rolling Eyes the car would not rev, it would start and drive on Rickover but would not rev. As soon as you tried to rev the engine management light came on and cut all revs out completely. I had to fit the old ecu when I got home to get the car drivable but after a few days of driving out I put the remapped ecu back on and it ran fine. Next I have this problem we are discussing. It may be linked I'm not sure?

With regard to the above many people suggested that the crank sensor was at fault, if it was dodgy then could it be causing the drop in power problem too Question

I will contact Gary and find out about the modified sensor. Thumbs Up

Cheers again
Post #132306 18th Mar 2012 2:20pm
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wslr



Member Since: 18 Jul 2010
Location: Wellington, Somerset
Posts: 581

United Kingdom 
Being a 99MY Defender, have you had a later flashable ECU, or has the map had to be hardwired onto the ECU PCB? Just thinking, because this could be the problem you are having - A map issue... Confused

Thing is, the MAF maxing out is usually something which occurs with some of the later flashed maps, and as it was behaving itself before, I'm not so sure the MAF issue this is the problem now - It could be an issue relating to either the hardware or software when the map was done.

Re the cranks sensor, it could be the problem, but it is likely to degrade quickly and you would notice the issues/symptoms changing or getting worse.

If I was you, firstly get any stored codes off the ECU. Possibly if they have the equipment, they can check the crank signal is OK with a Picoscope. Then, once you've got this info, either call Gary or post up here again.
Post #132443 18th Mar 2012 11:19pm
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amondeggs



Member Since: 06 Mar 2011
Location: Telford
Posts: 452

United Kingdom 1999 Defender 90 Td5 HT Woodcote Green
Just an update for those who may have similar problems or those who may have this problem in the future.

By chance I have recently discovered the source of the problem. On a long journey back from new forest the car began to make a chirping noise when climbing hills while pulling our caravan. This got progressively worse and we limped home.

This was caused by faild uj on front prop shaft. This was replaced with new and as if by magic the car performed brilliantly with no problems at all. The ecu does not cut the power out and the car now will accelerate beyond 70 mph with no problem. Took it up to 90mph today and chickened out at this point but it still wanted to go. I guess that the uj was causing excessive drag / friction that caused the ecu to cut the power?

Anyhow I'm pleased as punch with a car that works brilliantly

Thanks again to all those who contributed to by question Thumbs Up
Post #140608 20th Apr 2012 8:28pm
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LR90XS2011



Member Since: 05 Apr 2011
Location: bickenhill
Posts: 3641

United Kingdom 2011 Defender 90 Puma 2.4 XS CSW Galway Green
It wont be the UJ that caused your original fault, the car has enough power to destroy a UJ without any warning, the power problem dissapearing will just be a coincidence. It appears you are lucky the UJ warning you it was knackered and the power problem curing itself.
If I were you Id buy a couple of extra lottery tickets as you might be on a roll DEFENDER 90 TDCI XS,

I hope everyone is well and your land rovers make you happy
Post #140629 21st Apr 2012 4:29am
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T1G UP



Member Since: 08 Dec 2009
Location: Bath
Posts: 3101

England 2011 Defender 110 Puma 2.4 XS CSW Orkney Grey
Fuel? if the pumps iffy it won't get it in quick enough. TD5s are very dependant on 4 bar at the injectors.
Post #140645 21st Apr 2012 7:55am
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marsie



Member Since: 17 Nov 2011
Location: sheffieldish
Posts: 532

England 2010 Defender 110 Puma 2.4 XS CSW Galway Green
Got a similar problem on mine. Remapped(BAS),intercooler,new genuine airflow meter ,2000 my, but i think my fault is related to the boost pressure. All wastegate rods are free(and as far as i know standard length but when on a long pull eg. uphill 4th gear the boost goes upto around 20/22 psi and starts to fluctuate and at the same time the power drops off
i suspect i may need one of these Thumbs Up

http://bellautoservices.co.uk/products/td5-boost-box/

i will be having a run up to Petes soon to try and get to the bottom of it because other than that it flies Mr. Green
Paul Thumbs Up
Post #140673 21st Apr 2012 10:13am
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