New to TD 5 Defender - 'Misfire' Trouble

i have a 2002 Defender 90 TD5. It has started 'misfiring' / dropping out momentarily under acceleration / and even whilst cruising at speed resulting in a bit of a kangaroo ride. When this happens a lot it goes into 'limp mode' but stopping and starting again always gets me going again. Very frustrating since in between these 'jumps' she runs well and gets to 70 quickly.

Using this forum and the advice given I have:

1. Replaced the ignition loom today
2. Excercised the waste gate valve (God it's stiff but does move)
3. Washed out the engine loom plug connector to the ignition loom with brake cleaner
4. Checked the ECU plugs for oil - none found
5. Performed the Paddock YouTube test on the MAF
6. Cleaner the MAP
7. Cleaned the Crank position switch - it was oily
8. Cleaned the air temperature sensor
9. Disconnect the PSI tuning box it has

.... But no joy ... It's a promising ride aside from this drop out when I try any speed. It does get up to speed, but not smoothly.

I could do with some help if anyone has any other ideas. I'm wondering if the fuel delivery is OK. On turning the ignition key I hear the pump run for a good 30 seconds which seems like a long time. Could my problems be caused by air, or a leak? Or could there just be dirt in the injectors? Would a dose of cleaner in the fuel tank sort it out?

Any help gratefully received, Jim

Hi !
Last thing left would be the old injector seals, is it starting/idling ok?
Mine did a little misfiring before I got a replacement injector coded in.
Mark

Thirty seconds is about average for the fuel pump on my 02 TD5, so I wouldn't be alarmed at that. Do you have access to any diagnostics, it might be worthwhile plugging in and seeing if anything shows

I had it on mine and checked all that you have mentioned.
In the end my fuel pump was on its way out as was the fpr. I also replaced the injector seals so I'm not 100% what solved it

Hi, I really appreciate the input and all sounds coherent and plausible. I called Venture 4x4 Developments in Shipston on Stour and, although too busy to repair, they kindly said they'd be happy to plug it into diagnostics tomorrow. I'll report back on what that said.

Speaking of diagnostics - I have a MaxiScan MS508 and it cannot read the 2002 TD5 Defender - should it?

The Defender TD5s have a weird protocol that not all fault code readers can make sense of. it's not bog standard OBD. That's why a lot of people get themselves a dedicated unit like the Nanocom or Hawkeye or similar. Or there's a thing called Lynx now as well that can be run on a laptop.
Whilst a total failure of the crank position sensor will mean the engine stops completely, they can be semi-duff for a while and give you running problems and fault codes. When mine was on the way out my Nanocom showed 'high speed crank error' and the engine had a tendency to drop into limp mode at around 70. A new one, and it doesn't do that any more.

Thanks Brown, whilst I would have loved to have cracked this one using the power of the internet I clearly need outside help. I'll post up results tomorrow. In reply to markomate2 - starting is flawless, idles perfectly - it's just when I try to give it a little juice.

My guess is the turbo is overboosting causing the limp mode. Recycling the ignition resets everything until the next overboost event.

Do you have a boost gauge to confirm max boost pressure?

+1 on over boost. Should be at 14psi at standard but you can go to around 18psi before overboost.

Trying turning the boost down see if it solves the issue.

Nanocom can show the actual boost level

The diagnostics suggested that communication to the Crank Position Sensor had been lost but the chap there suggested it could also be the accelerator potentiometer and additionally suggested changing the fuel filter also. He cleared the faults and I've booked it in for a service Monday week. Turns out what I thought was the CPS was the fuel temperature sensor. Once I'd figured out where the CPS was (well hidden from view and only really accessible from underneath with the big rubber air intake hose removed) I cleaned the plug connections - this pulled apart so easily I don't think the clip was positioned properly so might have been loose. At the same time I installed new air and fuel filters.

The situation is now very much improved, but not perfect. It's certainly driveable but hiccups under heavy acceleration. I'm liking the turbo boost idea now but have no way of testing - I'll leave this to the garage. Also have a bottle of injector cleaner to put in just in case there's a bit of dirt somewhere.

I tested and set my waste gate by removing the small hose that feeds it and getting a bike pump with a guage and a fitting that fitted into the hose. I then pumped it very slowly and watched the waste gate open.
Mine had been wound in tight so wasn't fully open till nearly 24psi!! and had 5 or so threads showing on the waste gate! It did have a piggy back powerboat thing and a boost box. I set it closer to std at 18psi and about 9 to 10 threads on the waste gate arm

Hi, Guys, Funnily enough I think I just cracked mine on my 2000MY TD5 today. Been kangarooing for a long time now and like others I changed the injector loom thinking oil up the lead although the ECU connector looked clean so didn't go that far. Have been WD40ing the turbo waste gate pivot for a long time now and I think it gets better but not fully. Over the last few months I fitted a Raptor instrument panel and amongst others a Turbo Boost gauge and when I found when it kangaroos the boost pressure was up at 1.5bar, way over 1 and the needle flicked back and forth. So today I took the heat shield of the turbo/manifold and removed the little circlip holding the waste gate rod to the waste gate arm. I put lots of WD 40 over it and mole wrenched it to ensure fully free. I then found the waste gate rod did not line up with the arm spigot, it was about half a hole too short. Which meant in the normal state the waste gate was being pulled really hard closed (I assume) towards vehicle front. I lengthened the arm so it aligned and just slipped over the spigot, refitted it all and test drove it. And it goes like a rocket now up to 70mph and NO kangarooing. I think mine was being pulled closed too hard and probably with a fixed waste gate rod travel the waste gate itself was never fully opening. Anyway, I hope my quick drive will show a permanent fix over next few days.

Sounding familiar - certainly the between the filter change and crank position clean up the situation is infinitely improved - the residual issue sounds just like your experience. Must confess I never really understood the value of a turbo gauge - but looks like it does have a valuable contribution to make.

Well been driving my Landy for couple days now and the kangarooing has all gone. Drives smoothly up to the governor now without problems. Definitely the waste gate. Wish I'd checked that before changing the injector loom. Never mind, fixed now.

gazman said:

I tested and set my waste gate by removing the small hose that feeds it and getting a bike pump with a guage and a fitting that fitted into the hose. I then pumped it very slowly and watched the waste gate open.
Mine had been wound in tight so wasn't fully open till nearly 24psi!! and had 5 or so threads showing on the waste gate! It did have a piggy back powerboat thing and a boost box. I set it closer to std at 18psi and about 9 to 10 threads on the waste gate arm

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24psi! That is not good! Not without many other modifications bet it smoked like a thug as well.

18psi is a nice happy medium for untuned/mildly tuned TD5s. Below the over boost point but does make it more spritely!

I would buy a boost gauge off ebay, they are relatively accurate. Mine was £30 and reads 2 psi higher than my Nanocom does so if you fit it and it reads anywhere between 12psi - 16psi your fine. Very easy to fit, just fit a T-piece on the actuator pipe.

I fitted a good guage (stack) cost me about 90 quid. I've now set it to 18psi amd it never misses a beat

SOLVED - Hi and thanks to everyone for your help. I got it serviced today and at the same time they checked the waste gate and its setting is fine. So, from a position of sudden misfiring and going into limp mode at every drive I'm now running perfectly. Not entirely clear on the solution, but what it was not, was the injector loom - so its one / all of the following:

1. Poor Crank Position Sensor connection - most likely - thats what diagnostics suggested
2. Fuel and air filter change - possibly
3. A big dose of fuel / injector cleaner - that seems to have taken care of the final occasional hiccup

......... now to tackle why the Landy drops a load of water on my lap from the internal gutters when I park it facing uphill in the rain !!!