Under the weather 110 TD5

Can anyone give me some pointers please?
I have a 2001 TD5 110 with 85000 miles on the clock.
It have been serviced 300 miles ago a full service and using only genuine LR parts.
The problem is whilst driving it lacks power not much down but certainly the edge is taken off the performance.
It starts as always first time every time hot or cold.
It pulls away normally and accelerates through the gears just a little sluggish.
Come to a hill and you can feel it down on power, again not by much but it is down on power.
When driving at around 50-60 mph in 5th and then putting your foot down to accelerate the reduction in power is at its most noticeable. To the point I think I feel a misfire. Sorry to be vague on this but I does feel like maybe a wheel out of balance (they are not had them checked twice by different tyre fitters).
As I said it has been recently serviced so
new air filter
new fuel filter
the intercooler flushed out
The MAF sensor is recent gen LR (have tried another known good one)
MAP sensor cleaned
Turbo hoses changed
No EGR valve fitted
No oil at the plug under the rocker cover or at the ECU
No change in the fuel usage around 30-31 MPG

Any help appreciated.

check the turbo waste gate isn't sticking, search on here how to free it

You are doing well to get over 30mpg l can never get over 28mpg from my standard 110 TD5.

On mine the exhaust CAT was blocked and this caused a reduction in power, but l don't think they had a CAT fitted in 2001.

Mine also ran a lot smoother after an ECU reset at the LR dealer, before that it was rough at 2500-3000 rpm felt as you say like a wheel out of balance.

Are all the inter cooler hoses fastened tight after removing and cleaning it as it could be boost loss. Maybe some diagnostics live data could point in the right direction

goldypurple said:

check the turbo waste gate isn't sticking, search on here how to free it

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Waste gate is free to move, have also pressurised the actuator with a pump to see it working.

lightning said:

You are doing well to get over 30mpg l can never get over 28mpg from my standard 110 TD5.

On mine the exhaust CAT was blocked and this caused a reduction in power, but l don't think they had a CAT fitted in 2001.

Mine also ran a lot smoother after an ECU reset at the LR dealer, before that it was rough at 2500-3000 rpm felt as you say like a wheel out of balance.

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In the winter months it drops to around 28 mpg but over the last 17000 miles it has an average mpg of 30.97mpg
No cat fitted from factory
I do not believe the ECU can be reset on this early model (needs newer chip)

johnlad said:

Are all the inter cooler hoses fastened tight after removing and cleaning it as it could be boost loss. Maybe some diagnostics live data could point in the right direction

Click to expand...

I have pressure tested the intercooler and checked the hoses.
No fault codes appear on Hawkeye.
Have not checked live data what should I be looking for?

I believe it to be a fuel issue but I don't know for sure. The fuel pump makes all the correct sounds of a working pump but how do I check the fuel delivery pressure?
Also the fuel pressure regulator was replaced 20000 miles since with a genuine LR part could this cause the symptoms I am experiencing?
Inspected the turbo for damage and free spinning it also appears to work correctly.

When you say power is down, what happens when you floor it at 50-60mph? Acceleration should be steady and where legal you should achieve 85-90mph indicated.

Mine will sit happily at 75mph which is 3,000 rpm.

lightning said:

When you say power is down, what happens when you floor it at 50-60mph? Acceleration should be steady and where legal you should achieve 85-90mph indicated.

Mine will sit happily at 75mph which is 3,000 rpm.

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If I floor it at 50-60 it will gradually increase in speed not as rapid as it used to but never the less it will increase but I do get this sound/feel through the vehicle which is much like a wheel out of balance.
They are not out of balance and the props and wheel bearings are all good and no binding of the brakes.
If I take my foot off the accelerator at this speed the sound/feel stops instantly, foot back on the accelerator and it reappears.
What I am describing is not noticeable if traveling down even a slight incline, so not requiring so much power from the engine
I don t think I am describing two issues lack of power and a vibration but one interrelated issue.
I am getting fixated on a fueling problem but I could be barking up the wrong tree totally.

on live data, when flooring it on the motorway the maf sensor reading should get to around 600,
also map sensor should read around 210-230,
on tick over what are the cylinder balance's reading

johnlad said:

on live data, when flooring it on the motorway the maf sensor reading should get to around 600,
also map sensor should read around 210-230,
on tick over what are the cylinder balance's reading

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Cylinder balance = 1 -3 to +4. 2 -2 to +4 3 -2 to +5 4 -2 to +6 and 5 -3 to +3 at 745rpm
MAF up hill @ 60-65mph 4th gear 485
MAP up hill @ 60-65mph 4th gear 216

I'd say the maf readings are a little low, try unplugging the maf and see if it feels better

Any chance the exhaust could be blocked, (baffles collapsed etc)

Unlikely l know but you've checked pretty much everything else.

Tim4x4 said:

Waste gate is free to move, have also pressurised the actuator with a pump to see it working.

In the winter months it drops to around 28 mpg but over the last 17000 miles it has an average mpg of 30.97mpg
No cat fitted from factory
I do not believe the ECU can be reset on this early model (needs newer chip)


I have pressure tested the intercooler and checked the hoses.
No fault codes appear on Hawkeye.
Have not checked live data what should I be looking for?

I believe it to be a fuel issue but I don't know for sure. The fuel pump makes all the correct sounds of a working pump but how do I check the fuel delivery pressure?
Also the fuel pressure regulator was replaced 20000 miles since with a genuine LR part could this cause the symptoms I am experiencing?
Inspected the turbo for damage and free spinning it also appears to work correctly.

Click to expand...

My TD5 used to vibrate at high revs, but only when pulling this made me suspect a fueling problem, I did the usual rounds and one of the biggest improvements came when I changed the injector seals and fuel pressure regulator, I bought a regulator kit from e-bay and just changed the guts, the full unit is expensive and the outer casing should be OK mine cleaned up fine.

By the way its a bit fiddly but there is a fuel temperature sensor built into the pressure regulator I think I have seen somewhere that someone took it out and connected a pressure gauge using a flex hose to test the pressure.

johnlad said:

I'd say the maf readings are a little low, try unplugging the maf and see if it feels better

Click to expand...

Sorry I was unable to do anything until this afternoon.
I went out with Hawkeye set on live data and checked reading again three runs all on the same road an incline in 4th each run reaching 65mph
Run 1 Manifold pressure 215, Air flow 485, MAF voltage 3.72V
Run 2 Manifold pressure 212, Air flow 500, MAF voltage 3.80V
Run 3 Manifold pressure 213, Air flow 430, MAF voltage 3.68V
I then disconnected the MAF sensor and again had three runs up the hill manifold pressure again constant at 213 / 215
No Manifold pressure reading because sensor disconnected
Disconnecting the MAF did not make very much difference the vibration/feel was just the same, the performance not noticeably any different.
I was still able to reach 65mph in 4th at the top of the hill as I was when the MAF is connected.
Maybe the pickup through the gears was a little smoother but we are talking only marginally with the MAF disconnected

lightning said:

Any chance the exhaust could be blocked, (baffles collapsed etc)

Unlikely l know but you've checked pretty much everything else.

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The exhaust I believe is fine, it is two years old and a genuine LR system (the LR paper part description is still stuck to main box) , had no major nocks or bumps.

raywin said:

My TD5 used to vibrate at high revs, but only when pulling this made me suspect a fueling problem, I did the usual rounds and one of the biggest improvements came when I changed the injector seals and fuel pressure regulator, I bought a regulator kit from e-bay and just changed the guts, the full unit is expensive and the outer casing should be OK mine cleaned up fine.

By the way its a bit fiddly but there is a fuel temperature sensor built into the pressure regulator I think I have seen somewhere that someone took it out and connected a pressure gauge using a flex hose to test the pressure.

Click to expand...

I am fixated on the problem being fuel related. The fuel regulator is fairly new but yes this could still be a problem it was replaced with genuine LR part which has done approximately 20000 Miles.
I have not checked the Injector seals it must be worth me replacing them. I have a comprehensive service/repair history and there is no mention of them ever being replaced now at 85000 miles they have got to be worth a punt.
Edit should read 85000 not 5000

I can understand the fuel system obsession it seems to be the source of so many TD5 problems. The seals are not very expensive I bought the brit part OEM ones take some time cleaning the injector seats well if you do them. The pressure regulator kit is about £24 as I remember if you do it take care nor to lose the little filter which sits behind it in the head.
I also recently took the fuel filter head off gave it a thourough clean put in a new bleed valve and new copper washers on the four connectors which are screwed into it.

Update,
I have changed the MAF sensor both the old one and the new are genuine LR units no improvement with the problem.
I have had a good read of RAVE and in the TD5 section 18 engine management it has a description of how each of the sensors work and how a malfunction on any one of them may affect the engine running. Each could be causing the problem if malfunctioning and that includes the injectors.
Is it possible to establish the functionality of each sensor using a Hawkeye Diagnostic reader or will it have to be a Main dealer T4 diagnostic unit?

Further Update: NOW FIXED.
Having exchanged the MAF sensor the old one was less than 12 months old so was exchanged under warranty, I had a bit of a struggle to convince the main dealer it was faulty. Having to describe in detail the faults so that it could be sent away for testing he said he had never had one returned under warranty but he changed it. No difference when new one fitted still had the same issue so MAF not faulty (we will see if the dealer comes back to me).
Have now fitted new copper seals and O rings on the injectors and a new harness (no oil present in the rocker cover plug but changed it anyway).
After removing the injectors I had them ultrasonically cleaned.
Also whilst doing that work I removed the other three sensors AAP, MAP and CKP for a visual inspection and a clean up.
Whilst the AAP and the MAP sensors looked OK I cleaned the plugs and sockets with electronic cleaning spray and used a low pressure air line to dry out and remove the crud. The CKP was a different story.
The CKP was completely covered in thick oily muddy crud which I has to clean off the plug and the sensor. Having cleaned the sensor and around the area I removed the sensor and cleaned inside the socket and the plug at which point I noticed the insulation on the wires leading to the CKP had hardened and was cracking exposing the copper wire. This may have been allowing the oily crud to short out the sensor.
I made good the wire with new wire, made sure it was suitably insulated and refitted.
With everything back together road tested hey presto one TD5 back to full health.
I am not 100% on which was the cure, pretty certain it was not the injector harness, it could have been the Copper seals and O rings they were the original factory fit (I saw somewhere that original were all orange and replacements were either black or green) I removed orange o rings, or it could have been the wiring to the CK sensor.
Thank you all for your assistance.

Great to hear you have cracked the problem. In a perfect world it's best to do one thing and then check so you know what fixed it at the end, but working like that is a luxury few of us can afford.