TD5 power loss

I forget the units (volumetric flow for the MAF and pressure for the MAP) but at full power on a standard engine you should see 600-650 on the MAF and around 230 on the MAP. If you are getting good figures for the MAF, but low ones for the MAP, then as the air has to have gone somewhere, you probably have a leak.

Landrover6176 said:

What readings would I be looking at for the MAP and MAF?

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You have the whole list here(with blue) TD5 disco 2 maf and ambient air temp sensor

Update....

After fiting a second hand pedal I bought for £25....bargain.....it worked ..throttle felt instantly better and the power loss went for a good few weeks ....now its back and it worse

Full service been done with fuel filter etc, and going through some history its had a new wastegste modulator back in October last year I was going to change it.

My next move is to replace the injector harness which was done a few years back but might as well whilst I'm doing the rocker cover ....and I am thinking of a new actuator for the turbo too.

Someone was saying about the hi/lo switch on the transfer could be the culprit?

Just saving the pennies now as she's just had a new clutch and flywheel.

Landrover6176 said:

Update....

After fiting a second hand pedal I bought for £25....bargain.....it worked ..throttle felt instantly better and the power loss went for a good few weeks ....now its back and it worse

Full service been done with fuel filter etc, and going through some history its had a new wastegste modulator back in October last year I was going to change it.

My next move is to replace the injector harness which was done a few years back but might as well whilst I'm doing the rocker cover ....and I am thinking of a new actuator for the turbo too.

Someone was saying about the hi/lo switch on the transfer could be the culprit?

Just saving the pennies now as she's just had a new clutch and flywheel.

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Going on the commonsense basis that you changed something, then it got better, then it got worse, what is the connection between the throttle pedal and the rest of the car?
I've never had to play with this, but isn't there some sort of throttle potentiometer or summat, to provide the ECU with info on the throttle position? If it was me I would be looking at this.
Only other thing, i may have missed this on the other posts, but has the OP counted the threads on the wastegate actuator rod?

Stanleysteamer said:

Going on the commonsense basis that you changed something, then it got better, then it got worse, what is the connection between the throttle pedal and the rest of the car?
I've never had to play with this, but isn't there some sort of throttle potentiometer or summat, to provide the ECU with info on the throttle position? If it was me I would be looking at this.
Only other thing, i may have missed this on the other posts, but has the OP counted the threads on the wastegate actuator rod?

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I was thinking the same with the pedal connection, it all looks ok but need to check voltages etx, I've done myself a back and knee injury....icey pavement early morning haha so won't be getting down at it yet

Funny enough I was just searching for information on what the length of the actuator should be.

Today driving its fine up to a point then you can feel it hold off and then once you get to 2500 ish RPMs it launches like a rocket.

Landrover6176 said:

I was thinking the same with the pedal connection, it all looks ok but need to check voltages etx, I've done myself a back and knee injury....icey pavement early morning haha so won't be getting down at it yet

Funny enough I was just searching for information on what the length of the actuator should be.

Today driving its fine up to a point then you can feel it hold off and then once you get to 2500 ish RPMs it launches like a rocket.

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I have had similar and it was a filthy MAP/iat sensor. But it could be symptomatic of a dodgy throttle pot couldn't it?
On a bit of a sideline, is it an auto and is there plenty off clean ATF in it? Although this could not be temporarily cured by a new accelerator pedal!
Bloody modern cars. nothing is obvious, well not as much as used to be.

Landrover6176 said:

I was thinking the same with the pedal connection, it all looks ok but need to check voltages etx, I've done myself a back and knee injury....icey pavement early morning haha so won't be getting down at it yet

Funny enough I was just searching for information on what the length of the actuator should be.

Today driving its fine up to a point then you can feel it hold off and then once you get to 2500 ish RPMs it launches like a rocket.

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Sorry, just noticed this, the actuator rod should have 13 threads showing between the locknut and the end of the threaded portion.

Landrover6176 said:

I was thinking the same with the pedal connection, it all looks ok but need to check voltages etx, I've done myself a back and knee injury....icey pavement early morning haha so won't be getting down at it yet

Funny enough I was just searching for information on what the length of the actuator should be.

Today driving its fine up to a point then you can feel it hold off and then once you get to 2500 ish RPMs it launches like a rocket.

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Hope you recover from the injuries soon, what a sh!t!

Thank you,

Its mind boggling, before the only code coming up was driver demand fault. And its so intermittent like today it did it loads and then works perferct.

Its a manual, and so far far working through the list it could be I am running out of ideas now to be honest haha.

I know this sounds a stupid question but how is best to count the threas the troughs in the middle or the peaks.

Landrover6176 said:

Its mind boggling, before the only code coming up was driver demand fault. And its so intermittent like today it did it loads and then works perferct.
Its a manual, and so far far working through the list it could be I am running out of ideas now to be honest haha.

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So if you are running out of ideas just confirm you did the test i recommended here TD5 power loss as you didnt say anything about the result albeit is very important cos in some cases pump working only on LP can trigger the driver demand code on Eu3 engines while the TPS is faultless..

sierrafery said:

So if you are running out of ideas just confirm you did the test i recommended here TD5 power loss as you didnt say anything about the result albeit is very important cos in some cases pump working only on LP can trigger the driver demand code on Eu3 engines while the TPS is faultless..

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Hi, yes whilst it was at the garage for the clutch and flywheel they tested it and reported back it was ok.

As I was offered a pedal and it cured it for about 3 weeks I didn't further investigate it. and now back to loss of power etc, apart from 5th gear on my local A road, which is where I spend 90% of my driving its aboaulety fine.

Once I'm able to get out again after picking a fight with black ice I will run that test you recommended myself.

Landrover6176 said:

Thank you,

Its mind boggling, before the only code coming up was driver demand fault. And its so intermittent like today it did it loads and then works perferct.

Its a manual, and so far far working through the list it could be I am running out of ideas now to be honest haha.

I know this sounds a stupid question but how is best to count the threas the troughs in the middle or the peaks.

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Counting the threads is not too finicky. Find a knife with a thin sharp blade. Put the cutting edge of the blade against the locknut, with the blade edge in the thread trough. Angle it away from the lock nut at 45 degrees. Then slowly move it up towards the actuator, it will click as it goes from one thread to the next. It should click13 times before it touches the unthreaded part of the actuator. You can apparently go to 12 or maybe 11 threads before it starts to put you into the zone where overfuelling becomes a problem. So best to adjust it to 13 if it is not there or very nearly.
I also found this which is interesting,
https://forums.lr4x4.com/topic/85126-td5-driver-demand-faults/
particularly the bit from the guy who replaces the cable with a bit of trailer cable.
As it is an intermittent fault, if I was to stick my neck out, I would say there may be a wiring problem, What you are able to measure with the vehicle stationary may well change as the vehicle moves. All it takes is for a wire which is worn through the insulation, to just touch to earth, or to another wire similarly having worn through insulation.
A bit of trailer wire is cheaper than replacing the ECU. And it may be the case that when you replaced the pedal, you moved the wire a bit, out of the danger zone as it were, and then after a period of time the wire slowly moved back to the position where the problem recurred again.
This is not the only problem with wires wearing through their insulation, there is a notorious P clip holding part of the auto gearbox loom, which has a tendency to wear through the insulation but is difficult to see. You couold find it on the forum, although you don't need to cos you have a manual.

My back is playing me up more than usual, and my knees, which is new. I have a big worktop to fit soon and am dreading it, so I really sympathise with your plight.
Look after yourself and keep on with it. Sierrafery really does know what he is talking about so do take his advice. But don't abandon old skool careful examination of parts of looms, good earths etc.
Best of luck.

I appreciate that thank you for that information, that thread was helpful and offered a great insight. I will when I can get down and check the wiring from memory when I changed the the pedal from what I could it looked OK under the dash.

This is my first land Rover so still learning alot, bit frustrating this problem as I'm stuck at the moment untill I'm on a better shape to start climbing around again haha. Its disheartening slightly but I still genuinely love this machine!

I'm definitely leaning towards a faulty wire being so intermittent where is disappeared for weeks and comes back then disappears again and its one of those things where it will never happen whilst in the garage on a test drive which is frustrating haha, I will check the thread count but as I say and rightly so yourself its so intermittent, that if it were the length of the actuator itself then it should be happening my frequently unless its the actual actuator failing.

Sorry for all the amateur questions but whilst laid up all I can really do is read, where would be the best place to start learning about replacing the ECU to pedal wiring would you think?

Landrover6176 said:

I appreciate that thank you for that information, that thread was helpful and offered a great insight. I will when I can get down and check the wiring from memory when I changed the the pedal from what I could it looked OK under the dash.

This is my first land Rover so still learning alot, bit frustrating this problem as I'm stuck at the moment untill I'm on a better shape to start climbing around again haha. Its disheartening slightly but I still genuinely love this machine!

I'm definitely leaning towards a faulty wire being so intermittent where is disappeared for weeks and comes back then disappears again and its one of those things where it will never happen whilst in the garage on a test drive which is frustrating haha, I will check the thread count but as I say and rightly so yourself its so intermittent, that if it were the length of the actuator itself then it should be happening my frequently unless its the actual actuator failing.

Sorry for all the amateur questions but whilst laid up all I can really do is read, where would be the best place to start learning about replacing the ECU to pedal wiring would you think?

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I am not sure if it is in there, but the RAVE manual might help. I have to admit I would start by just physically following it from the pedal, but with a dodgy back etc that will not be easy. Looking for obvious places where there are sharp bends or where it could rub against something.

If the actuator is failing i cannot imagine it being OK some times then not for others, it is very simple: a canister, a connection to a tube, a diaphragm, a strong spring, an actuator rod connected to diaphragm and the bolts to hold it to its mount. I don't think they go wrong often. Have never read of this on here. To go wrong it would likely be a split in the diaphragm or a broken spring. The tube connection could be iffy, i suppose.

Stanleysteamer said:

I am not sure if it is in there, but the RAVE manual might help. I have to admit I would start by just physically following it from the pedal, but with a dodgy back etc that will not be easy. Looking for obvious places where there are sharp bends or where it could rub against something.

If the actuator is failing i cannot imagine it being OK some times then not for others, it is very simple: a canister, a connection to a tube, a diaphragm, a strong spring, an actuator rod connected to diaphragm and the bolts to hold it to its mount. I don't think they go wrong often. Have never read of this on here. To go wrong it would likely be a split in the diaphragm or a broken spring. The tube connection could be iffy, i suppose.

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I agree with 100% on the actuator, I am going to try what Sierrafery posted about the voltage tests myself when I can.

Once I'm fit and ready I will travel the wires, going to search for a diagram to see the wiring, give me something to read about haha. I'm a coach driver so this little fight with black ice I had has put me out of action, so much for the anti slip boots haha

Have you still got the old pedal assembly?
If so test that so you know whats what, then test the new 2nd hand one.

lynall said:

Have you still got the old pedal assembly?
If so test that so you know whats what, then test the new 2nd hand one.

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I have yes, which is lucky as I was going to chuck it

Landrover6176 said:

I have yes, which is lucky as I was going to chuck it

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Hang on I will find some pics.

lynall said:

Have you still got the old pedal assembly?
If so test that so you know whats what, then test the new 2nd hand one.

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Yeah I was also thinking along the lines of this sort of thing, maybe even replacing it back in to see what happens.

Pic as promised, 2001 model was losing power and causing driving issues, new pedal fixed it, so Iirc I measured the volts/ohms? and one track was dodgy so opened it up to find the worn bit in the top track.
I believe some pedals have two tracks and later ones have three tracks? they work by comparing readings and should always add up to say 100, 1 track reads 78 so ther other needs to read 22 ie total of 100, and so on, not sure if fgiures are read/measured that way, just my way of explaining it.