Hi All and a very happy new year!

I have been the owner of a DII (2001 GS) with EU3 TD5 since June 2016. Drove perfectly for about 6 months. Ever since it has suffered the common poor running issues. It does still have plenty of pull and cruises fine but at slower speeds and local roads it 'misses' and also hunts at idle. Sometimes it is so bad I have to dip the clutch when slowing to a stop to prevent it being so erratic that it really makes the vehicle judder.

I have done the following work with no success:

Genuine Injector Harness (no oil in red ecu plug)
Injector Seals (copper washers and rubber o rings) (double checked injector set ups)
All new sensors (Genuine) (AAP, MAF, MAP, Crank, Coolant and Fuel Temp)
Genuine Fuel Pump and Fuel Filter Housing with new filter and new valves (Non return and Air Bleed)
Fuel lines checked and no apparent leaks - tank removed, cleaned and breather checked
Fuel Pressure Regulator Changed
Inlet Manifold Gasket renewed
Exhaust Manifold replaced with re-skimmed one, new gasket and new studs/nuts
Wastegate Modulator and pipes renewed - even ran it like the defender for a few days with no change
Turbo to Intercooler pipe removed and air discharge from turbo checked with waste gate manually operated
Wastegate free and actuator appears to be working
Land Rover Specialist had vehicle twice - no success, although sensors were replaced as a result
No fault codes showing and injector readings appear normal, as does throttle signal
New vacuum pump
New Water Pump and Coolant
Can't find any air leaks in hoses and no associated noises but open to advice on how to check properly

It did have a stage 1 remap by bell auto services with previous owner in Yorkshire. The EGR has been removed as well. ACE system removed also and converted back to normal springs.

I'm doing some other work soon (prop shaft UJs and Diff Seals). It will also need a new clutch/flywheel and associated stuff as well. Spigot Bearing or Release Bearing is noisy when cold!

She's on a strong chassis. I've done hours and hours of preventative work on that and body mounts. New cv joints, new drop links. Everything else appears serviceable.

Well, I'm now at a loss. If I have missed something obvious I'm happy to be told. Could the ECU or Engine Loom need work? Glow Plugs and/or wiring? Relays? Fuses all seem fine. They're the next things I'm thinking. The symptoms do go away mostly (but not completely) by disconnecting the AAP sensor in the air filter box and she still hunts for about 5 seconds when returning to idle. I have cleaned all the earth points I can find - not saying I've found them all though!

Any thoughts and advice would be most welcome. I have changed oil and all filters approx every 5k miles since owning it. Had 123k when bought and now has 146k.

Best Regards, James Gilbert.

Clutch switch sounds like your problem

DiscoDevon, many thanks. I will try that. Never occurred to me. Cheers.

Let us know how you get on please.

Sure, will do.

Just to up date, new genuine clutch switch has arrived. (Been away for work over the last week). I aim to fit it in next couple of days, or over the weekend. I will report back!

Hi All, I've just fitted the new clutch switch. She still hunts for a few seconds when returning to idle but the general hunting and 'missing' at idle and when driving seems to have gone. I'm away for work all this week but will monitor while driving around when I'm back. Thanks for the suggestion DiscoDevon.

Hi all. Sorry to say all the symptoms have come back again. Am I crazy or could I be on to something, thinking temperature is affecting it. Seems really bad now we are having very cold mornings. She gets better as the day goes on. Anyway, I have a colleague who is borrowing a friend's diagnostic computer in a couple of weeks. Can't remember which make he said it was but we'll see if he can suss anything. If I carry on trying, I think I'm on to air hoses and intercooler as physical causes (although I have tested these and they seem ok with no apparent leaks). Maybe glow plugs and even the ECU itself??? Bad alternator or battery (voltage - although, again, tests don't indicate any problems). After that, I'm back to the beginning - have I just been unlucky and one of the new genuine sensors is duff??? The hunt for the cause of the hunting continues :-(

Someone else said the head gasket could be going but I don't have any of the usual warning signs. Coolant level is fine, she doesn't smoke at all. Oil level is fine. And she still has plenty of power. Oh well, I'll see how long I'm still allowed to spend my pocket money on her!!!!

I think you may need to bleed the brake /clutch system when changing the switch so do that first if you haven’t

Thanks. Yeh, already bled the system to be sure. Took my wife's car to local garage yesterday and one of their chaps has a couple of TD5 Discos. After everything I've tried so far he thinks it is likely to be the ECU and possibly something to to do with the stage 1 remap done when previous owner had it. He's told me to look up TD5 Alive in the midlands and speak to them. (Remap was done by a company called Bell Auto Services I think but I only know that from the advert when I bought it 3 years ago). I'm thinking in the direction of ECU but this is way above my capability. I don't claim to be an engineer but am ok with the physical stuff on diesel engines - electrics and ECU systems, not! Will look up this company TD5 Alive. Yesterday morning she drove perfectly from home to my daughter's school and then to work. Sat all day outside my office and then drove home like a bag of .....!!!!! ????? I'll keep you all posted. Away from today until next weekend though (Travel quit a bit for work).

Well, been a very long time since I posted but thought I'd put an update to my TD5 running issue. After reaching a final and complete blank, I took it to a land rover specialist in Cornwall recently, where they diagnosed the hunting and erratic running to injectors and also the flywheel being well overdue for replacement. Not a cheap job (although I thought a fair price) but injectors changed and flywheel, clutch (and all associated bearings/seals) changed..... now running like new! Apologies its been so long but normal life took over for a while and now finally got back to sorting this! Hope everyone is safe and well in current times!!!

Good that you found a garage that knows their way around a d2