View Full Version : TD5 lack of power, slow to rev
nakedbarra
31st January 2025, 06:32 AM
Hi folks so I have a new to me 2000 TD5 defender, when you press the accelerator pedal the engine revs very slowly until about 2600rpm until the turbo kicks in.
I replaced the MAF which was faulty and that did create a little more power but didn't fix the slow peddle response as its hard to get going on a slight hill until the turbo kicks in still around 2600rpm.
The head was redone prior to my ownership but cat get any info of the history before the head being done.
replaced the original injector loom, not sure why it wasn't done at the same time as the head and the ECU doesn't have oil in it but has oil to the plug.
The waste gate is free and turns smoothly.
Any ideas as to why it lacks power and is slow to rev up?
Cheers
Discofender
31st January 2025, 07:04 AM
Do you have access to a Nanocom to confirm sensor readings? The AAP, MAP, and TPS can all give erroneous readings that will affect power (also need to confirm the new MAF). RAVE gives the input output voltages to check with a multimeter if no Nanocom.
Otherwise, check everything you can, such as air filter blockage, collapsed turbo pipe, blocked intercooler, whining/noisy fuel pump could be giving low pressure to FPR.
There are a number of things that could have been missed in the head exchange. Was it remapped?
There's lots to check, and plenty of real experts on here (not me) will be able to assist if you can describe the symptoms well and list what you've checked.
How cold is it where you are?
Cheers Discofender
Tins
31st January 2025, 07:21 AM
Something is awry. DJ has covered the obvious checks. I would add that I would expect boost before 2600. I’m wondering who did the head. Could the timing be a tooth out? Were the injectors coded properly? ( Don’t think that would cause your issue but…). Check your f the exhaust is restricted.
Some random thoughts. I am no expert either. If you are keeping the car I would recommend getting a Nanocom. They are not particularly user friendly but they are pretty much the only diagnostic tool you can get for a TD5 and pay for themselves eventually.
if you’re near Quebec there’s a LR mechanic at Sherbrooke.
shack
31st January 2025, 08:08 AM
Really hard to Diag this stuff remotely without any hard data.
Based on the symptoms and history my first guess would also be timing.
It won't be incorrectly coded injectors.
If you unplug the MAF and MAP/IAT the ECU will default to some programmed readings that are low, but still shouldn't stop it revving.
Other things to check if not mentioned above are:
Is the fuel pump running.
Are the injector bump settings correct.
Does it have bad blowby.
Are there any errors logged in the ECU.
They aren't in order, so pick the easiest quickest ones first.
BTW, 5 pumps on the throttle with the ignition on should put the fuel pump into a purge mode and it will cycle on and off for a while.
The defender has no soundproofing around the fuel pump (or anywhere else) so the pump is really easy to hear, possibly even when you are in the car with the engine off.
A number of these things are listed in the 2 posts above, not trying to steal anyone's thunder, just reiterating....
AK83
31st January 2025, 03:50 PM
....
The waste gate is free and turns smoothly.
Any ideas as to why it lacks power and is slow to rev up?
Cheers
I would double-triple check the wastegate.
While its free moving, have you checked length of rod.
This would be first go to point.
You said head done prior to ownership, maybe someone previously had turbo disassembled, and when put back together they got the length of the rod 'too long'
If the rod is just ever so slightly too long in length, it could be set to just slightly open the wastegate and instead of pressure spooling up inside, it's leaking paste wastegate and not giving reasonable boost lower down.
Once you get to that 2600rpm stage tho, there's enough pressure in the exhaust to give some boost.
Easy to check, disconnect rod at wastegate and make sure that the wastegate actuator and rod length has some 'pulling' force back, to force the wastegate shut.
That is, if you disconnect the rod at the wastegate and can, relatively easily get the rod back onto the wastegate arm .. it's too long. You should have to pull the rod out of the actuator just a little to hook it onto the pin.
(or do it the bludgers way and just add some compressed air to the actuator to push it out and hook it to the pin).
Tins
1st February 2025, 09:49 AM
A number of these things are listed in the 2 posts above, not trying to steal anyone's thunder, just reiterating....
Wouldn't worry about that. You probably do have "expert" status.
Tins
1st February 2025, 09:51 AM
Arthur makes a good point re the wastegate actuator. RAVE specifies a number of thread turns, which I can't recall atm.
sharmy
2nd February 2025, 06:36 AM
10 comes to memory but I can't be sure
RANDLOVER
2nd February 2025, 08:29 AM
I still fancy the fuel pump as the cam driven injectors can syphon fuel from the tank, so higher rev's means better fuel supply. I actually got a speeding fine uphill on a freeway when mine wasn't working properly! You should hear the pump whining under the car when you turn the key on.⁹
shack
2nd February 2025, 02:39 PM
I still fancy the fuel pump as the cam driven injectors can syphon fuel from the tank, so higher rev's means better fuel supply. I actually got a speeding fine uphill on a freeway when mine wasn't working properly! You should hear the pump whining under the car when you turn the key on.⁹I have had a TD5 with a failed fuel pump, it still ran at idle but would not rev very well, the harder it tried to rev the worse it ran.
In the end if running long enough it would start to miss entirely on one cylinder.
That was without a completely failed pump... I.E. no running at all.
Graeme
2nd February 2025, 04:35 PM
I made the mistake of removing the fuel temperature sensor to check fuel pressure using a gauge on a friend's that was behaving as you described Shack. It didn't run at all after that as the tank pump wasn't operating.
Tins
2nd February 2025, 04:48 PM
Interesting idea about the fuel pump. Never thought of that.
As the head has been off, what about the FPR? I dunno, just a thought.
nakedbarra
3rd February 2025, 05:36 AM
So I found a local guy with a nanocom and we cleared codes and after a drive it got a little better but still not there yet, any TD5 mechanic's in the Newcastle area?
Map and Maf replaced, wastegate rod is good.
Its better but I will still keep working on it
shack
3rd February 2025, 06:22 AM
So I found a local guy with a nanocom and we cleared codes and after a drive it got a little better but still not there yet, any TD5 mechanic's in the Newcastle area?
Map and Maf replaced, wastegate rod is good.
Its better but I will still keep working on itDid you record a log while driving?
nakedbarra
3rd February 2025, 04:41 PM
No We didnt, I am thinking it could be the pump either failing or diesel sludge as a the truck has sat for long periods between driving by the previous owner
Tins
3rd February 2025, 05:15 PM
No We didnt, I am thinking it could be the pump either failing or diesel sludge as a the truck has sat for long periods between driving by the previous owner
Hmm.. Where you are it can get cold ( duh ), and damp. The fuel could be suss, so the filter could be clogged, and the pickup screen too. Worth a look.
DazzaTD5
4th February 2025, 05:55 PM
I'm with 2 others in saying fuel pump, if it was a D2 TD5 it would be a given, for some reason Defender TD5 fuel pump failures are rare...
shack
5th February 2025, 06:58 AM
I'm with 2 others in saying fuel pump, if it was a D2 TD5 it would be a given, for some reason Defender TD5 fuel pump failures are rare...That would no doubt be due to the superior engineering and attention to detail given to every Defender before they had to push it off the assembly line.
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