Poor low end power after remap defender TD5??

Hi all,

I've just had a stage 1 remap on my 2001 defender TD5.

Previously it was running poorly with the MAF sensor plugged in so bought a new genuine sensor and replaced it however even then the car still ran better with the MAF unplugged. (after all error codes cleared ect was still sluggish until turbo kicked in) Even though not a single fault could be found I just ended up driving it without MAF as it was so much better!

Before the remap I plugged it back in and had a full diagnostic - All numbers were fine. After the remap It runs amazingly well with loads of power as soon as the turbo kicks in but at low RPM its still really flat . You can floor it in gear 1 and it will accelerate painfully slowly until (what I imagine) the turbo kicks in and you really get pushed back into your seat!

Its at the point where its almost dangerous pulling out into the road as its so slow from stationary (that is until turbo kicks in then its really impressive now!)


Does anyone have any ideas about this - really confused here! Any help would be really appreciated!

Many thanks

Alastair

Does it rev properly when first started?

EGR Blanked?

Can't help the problem, sorry, but why didn't you get it running properly before the remap?

Just can't understand why you'd remap a vehicle that wasn't running correctly, all that might do, as it has, is exacerbate the problem, not mask it!

Bet it's not fun to go laning in either now ..

No takes about 10 secconds of 'thinking time' regardless of pedal position before the emgine becomes responeive .

Yes it is.

Completely see your point. Everyone said to me it was running fine despite the fact that it clearly had better performance with the maf unplugged. They were basing this on car diagnostics and a full investigation with no problems found. They said it must be something ecu related.

Thing is it has improved a little but but there's still an obvious fault with something somewhere as I'm sure it shouldn't run better with the maf unplugged!

Alastaird said:

No takes about 10 secconds of 'thinking time' regardless of pedal position before the emgine becomes responeive .

Yes it is.

Click to expand...

Not 'getting at you' as such, trying to understand ..

Maybe the thinking time is something not related to the MAF at all, TPS perhaps, or the management system .. can you run live diagnostics and get a 'view' of the numbers on the road? I'm presuming it only shows up when moving and that there's no lag when stood and ticking over and the loud pedal is pushed?

check the wastegate on the turbo if its taking ages to kick in ?

wonder if it could be seized a bit and then the boost pressure finally gets it to open after a while ?

sounds like the wastegate is sticking, spray wd40 on the pivot point when turbo is cold and work the wastegate arm with molegrips until its free moving

Dam the Dr beat me to it

Of course - really appreciate any help!

Once ticking over even if you floor it it is painfully slow then as soon as turbo kicks in wow its quick...

As far as starting it goes, it takes a while before the turbo is able to spinn up so accelerates poorly regardless of engine rpm (this onky lasts 5 to 10 secconds so not a problem)

Thanks for the help!

I'll go try the turbo now.

Thanks everyone!

Turbo moving completely freely. Used some wd40 on it anyway. Just thinking from a mechanical point of view what the problem could be?

As I mentioned, it had full diagnostics whilst driving and all numbers were perfect...

you could try cleaning the fuel pump filter in the tank

turbo moved freely but put a bit of wd40 on ends of rod just to be sure...

Any other ideas?

Really appreciate everyone being so helpful thanks!

Mine is similar. No re-map but takes about 10 - 20 seconds to rev properly, once on the road is perfect.

EGR blank
Air filters fine - near new but checked anyway
No oil in red
MAP clean
MAF appears fine but does run a little better unplugged
New injector harness - recently cleaned too
Wastegate is tough to move but it does.

Ali - Check all the above too

There seem to be two things conflated here:
1)takes a little while after cold starting before it will actually rev. Mine has always done that.
2) once on the move, the bottom end is gutless and so it takes a while to actually get within the operating range of the turbo.

This second point - mine suffered from. I ran a few thousand miles with Millers injector cleaner/ cetane improver (costs about £2.50 to dose a full tank on the 110). This worked really, really well. In fact, I saw fuel economy figures go from 27MPG to 30.9 (worked out over quite a few tankfuls - I do 500miles pw). Additionally, I found that whereas before it would simply not tolerate 30mph in 5th, even without loading it - it does so quite happily now.
Although it's still faster with the additive (showing that supermarket fuel isn't the best) - it's also smoother at the low end without - showing that my injectors perhaps weren't atomising as well as they could

One final point - I tried that thing of putting about 200 ml of 2-stroke in a tankful - much smoother and quieter at revs! - even seemed (could be psychological) to rev more easily
I still think a modest remap would improve it further.

Interesting. Ill try out this centane stuff see how it goes. Doesnt really bother me too much considering when you first start up your usually pulling out of a drive/parking spot slowly etc..

bankz5152 said:

Interesting. Ill try out this centane stuff see how it goes. Doesnt really bother me too much considering when you first start up your usually pulling out of a drive/parking spot slowly etc..

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I should say that, although I noticed some improvement in the first tank, it was in subsequent tanks that I really noticed (I suppose that's the injector cleaning/ better atomisation)

Thanks Bankz - yeah i'm exactly the same as you on all the points you mentioned!

Maybe i'll just stick with it. after all you don't but a defender as a 'fast car'!

There are a few more mods I'm thinking on mine such as a decat and larger intercooler - hopefully these will help.


thanks for your help

Decats all well and good but you have to keep the cat for the mot.

Larger intercooler is good but to be fair, soon as you go off road its more **** to clean out.

Scroll through the Td5 section theres plenty of relativley cheap mods that can be done to increase bhp/torque/mpg

Have you gone back to the remapper?