Defender TD5 flat spot woes..... Don't know what to do!

Alastaird · Apr 13, 2013

Hi all,

To cut a long story short, I had terrible cold start acceleration performance. 2001defender TD5 Car was a menace to pull out into the road as took good 20 sec to get any sort of acceleration or power....

Anyway I unplugged the MAF sensor and immediately got unbelievably good performance - best ever so far with my landy.

Concluded was MAF problem as have already blanked off EGR months ago.

Bought new expensive genuine LR MAF and fitted it. When Plugged in the acceleration problem is even worse... there is a massive flat spot at low RPM's takes about 30 sec for any sort of power to develop... truck is undrivable with it plugged in.

I'm thinking this is an airflow problem?? APP sensor?

Does anyone have any ideas about what to do next? I finally thought I was going to get a few trouble free months with the landy but it thought otherwise.... :mad2:

Thanks so much in advance for any help!
Cant thank this forums members enough for all their help so far...

Alastair

ratty · Apr 13, 2013

have ya tried doing this yet?

http://www.landyzone.co.uk/lz/f67/removing-cleaning-td5-map-sensor-198286.html

Alastaird · Apr 13, 2013

Will give it a go thanks - Could this cause similar symptoms? i.e car functions fine with MAF unplugged?

timtheenchanteruk · Apr 13, 2013

yes, dunno about the fender in particular, but most motors, loose a sensor (such as unplugging the MAF) it goes to a default setting, cos it needs readings from all the sensors to work properly.
if everything is working properly, unpluffing one sensor would lead it to being more sluggish than normal, possibly a reduction in boost (depending on the engine) if somthings being misreading for a while, unplugging can actually improve performance.
If cleaning the MAP doesnt work, a diagnostics would be a good call, see if therees any codes stored, or at least use some RTI to see what sensor is out of range.

Alastaird · Apr 14, 2013

So to add to the confusion I've just cleaned the MAP sensor (Was pretty clean when I took it out tbh) and the performance is marginally better... Truck still pretty much unsafe on the roads as just doesn't have any low end acceleration at all.

Goes like bat out of hell when MAF unplugged....? (as I said this is brand new genuine LR MAF)
Just a bit dangerous to drive on london roads!

WHat else can I try?

Thanks for the help everyone!

johnlad · Apr 14, 2013

youve put the air flow meter in the right way round i assume??

Alastaird · Apr 14, 2013

yep course.... only fits in one way.

Alastaird · Apr 15, 2013

So just plugged in diagnostic test and cleared all error codes with new MAF. Car starts well but still no low end power - turbo takes ages to kick in? Once it does car runs great.

Is there any way to make the turbo kick in lower down?

As I understand it in a defender TD5 all exhaust is pushed through turbo anyway unless pressure climes high enough to open waste gate. With this in mind is there realistically any way of making it come in earlier.

I really want the low end grunt it used to have back!

Shifty1962 · Apr 15, 2013

You may have a partially stuck open turbo wastegate.
Have you checked for air leaks in the turbo hosing?

Alastaird · Apr 29, 2013

hi shifty - yes checked all that. Local GArage had a look and said they can find nothing wrong.... All data from MAF sensor perfect.

They think down to faulty ECU - Do these ever just fail?

DJ Xan · Apr 29, 2013

Ecu fills with oil across bottom of circuit and causes plenty of issues. Drove mine till the ecu just gave up.
Had it read and told needed replacing. New in old out drives fine now. Expensive though £660 for the new one.

GINGE · Apr 30, 2013

DJ Xan said:
Ecu fills with oil across bottom of circuit and causes plenty of issues. Drove mine till the ecu just gave up.
Had it read and told needed replacing. New in old out drives fine now. Expensive though £660 for the new one.

how much???

Jesus thats not cheap!

I have a spare one, i didnt know i was sat on a gold mine!

DJ Xan · Apr 30, 2013

BIG_GINGA_BEARD said:
how much???

Jesus thats not cheap!

I have a spare one, i didnt know i was sat on a gold mine!

Yes mine was having a very deceitful conversation with the reader. And would also work like noting was wrong when it felt like it. So doing the logical I replaced all the usual first (pump, harness, seals).
Expensive Xmas pressie from the Landy.

Defender TD5 flat spot woes..... Don't know what to do!

Alastaird

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ratty

I'm not special I'm limited edition

Alastaird

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timtheenchanteruk

Well-Known Member

Alastaird

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johnlad

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Alastaird

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Alastaird

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Shifty1962

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Alastaird

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DJ Xan

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GINGE

Greenlane liker, bobble hat hater

DJ Xan

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