TD5 engine rough running & power loss

Hi all,

Been reading all the posts relating to this as I currently have the same problem on my '53 Disco auto.

Problems are as follows:

• Engine will start fine then within either a few seconds or several miles engine note changes and it shudders, power loss and feels as though its running on 3 cylinders.
• Usually if I pull over, turn off then back on again the problem disappears (although this is working less and less, recently it doesn't always cure the problem).
• The rough running seems to happen more frequently with a cold engine.
• The problem will not stop unless I swich off and re-start.

I have recently had the injector loom changed (due to the common "oil in the ecu plug" issue)

Just had a diagnostic check performed, whilst it was running rough, and it had logged two fault codes with injectors 2 and 5 (sorry can't remember the actual fault code wording).

The mechanic (who changed the loom) suggested he change it for another genuine LR loom as a start as it may be faulty, although he said he had never known a faulty LR loom.

Anybody have any ideas, from their experience, as to what else it might be? (thanks to "Johnlad" who I've already been in discussion about this).

Help greatly appreciated!

Those fault codes are very important to be known... read codes again to see if they're still there after the loom replacement...and by the way, did u clean and dry well the ecu plug?

Have a read at this... http://www.landyzone.co.uk/lz/f50/td5-misfiring-cutting-out-problem-finally-solved-125039.html

It'd be interesting to determine from fault codes if injectors are 'peaking' (potential shorting between injector cables or ground) or 'open-circuiting' (lack of continuity). While oil in loom can cause these, there is also the chance of physical damage to the engine harness.

Once the engine detects one of the said anomalies it will 'disable' the respective injector/s. Hence when restarting (Ctrl+Alt+Del) all is back to normal...

IME oil in loom problems usually kick in once the engine is up to running temp since oil becomes slightly more conductive (less resistive should say) and can cause 'micro shortings' between pins within an oil flooded connector. An injured engine harness on the other hand can give trouble at any time.

I would 1st make sure there is absolutely no oil left in the harness connectors and red plug. Even if you've recently changed the injector harness in all likelihood the engine harness is still full of oil which continues its slow migration towards the ECU (red plug).

If find oil in the red plug, take the ECU out and have a look at the 4 tiny ports on the backside, oily stains would indicate oil has got in...

Rgds
Matt

Thanks for your replies, will give the ecu plug another clean (can't do any harm can it). The last time I cleaned it I sprayed (with electrical contact cleaner) the ecu socket and left it to dry raised up so the traces of oil ran out, whilst I cleaned the plug.

Just as an update it started fine after being left overnight, then within 10 seconds the problem started. Switched off to re-start again and it wouldn't re-start. Turned over and started (well rumbled) for a couple of seconds then died.

I will ask the mechanic to write down the fault codes on Monday if he plugs his diagnostic in again. The description of the injector fault codes "Mturri" quoted seem like the ones it brought up however I can't be 100% certain.

Lets hope replacing the loom again will fix the problem! (and another clean of the ecu plug etc). Although I can see this problem being a pig to solve.

Again thanks for all the advice.

see how to clean the ECU here www.discovery2.co.uk / Workshop /Injector Harness

The obvious call is electrical, but how about an injector seal problem?

When the diagnostic check was done, was it possible to monitor some live data while the engine was running? If not it would be worth finding someone who has Testbook/T4.

Update for today.........................

Wouldn't start at all yesterday after being left overnight so didn't use it all day and night Saturday.

Been out this morning (Sunday) so after lunch tried it again. Took ages to start (rumbled then died every time after about 20 trys), lots of white smoke when it did eventually. Running rough as I took it for a run around the back lanes (did about 5 miles). Stopped and re-started it at least 5 times and always the same, rough.

On the road into the estate where I live, I pulled over and stopped, re-started and ran sweet as a nut. Parked on the drive, left it idling for at least 15 minutes and no problem - idled like it should. Turned off and re-started 3 times - no problem.

Seems to run as it should once its warm - any ideas anyone?

Taking it in for the injector loom to be changed again tomorrow. It must be electrical?

sorry, i'm not familiar with english "plate numbers" ... what year is '53 plate...if i suspect well according to symptoms it could be '99-'00...and if it's so ECU missbehaviour might occure(MSB101183/4 ECM's are very unstable)

fuel?

sierrafery said:

sorry, i'm not familiar with english "plate numbers" ... what year is '53 plate...if i suspect well according to symptoms it could be '99-'00...and if it's so ECU missbehaviour might occure(MSB101183/4 ECM's are very unstable)

Click to expand...

53 plate is a late 2003 model

The mechanic who plugged his diagnostic in didn't think it could be fuel related. If it was why would it run perfectly when warm?

Its a mystery and b1oody frustrating!

Discosingo71 said:

The mechanic who plugged his diagnostic in didn't think it could be fuel related. If it was why would it run perfectly when warm?

Its a mystery and b1oody frustrating!

Click to expand...

Sorry about the last rant, I was typing at the same as my lovely kids were arguing.........

Just started it again on my way out for tea and started and idled without any problem, although it was still warm. Lets see what happens in the morning when its time to go to work........................

had a similar prob to yourself and it ended up being injector seals. It would cut out whenever it wanted and was an absolute git to restart and then could run fine for 20 miles and sit on the drive ticking over for twenty minutes but next time I tried to start it chuff all.might be worth a good dose of looking at.

cuza68 said:

had a similar prob to yourself and it ended up being injector seals. It would cut out whenever it wanted and was an absolute git to restart and then could run fine for 20 miles and sit on the drive ticking over for twenty minutes but next time I tried to start it chuff all.might be worth a good dose of looking at.

Click to expand...

Thanks for the suggestion. Just tried starting it again, now its cold, and surprise surprise same old thing. Obviously when its at running temp the problem goes away. Will discuss with my mechanic tomorrow, mention the injector seals, and also see if he's come out with any ideas over the weekend. Isn't Land Rover ownership fun......................

Last update of the day! Just been out and tried this:

• Turned ignition on and left for 3-4 mins, could hear fuel pump whirring (not noisy).
• Waited till it stopped. Pumped gas pedal 10 times (engine management light started flashing) - this is all with ignition on.
• Pump started priming again - waited till it stopped.
• Turned key to start...............fired up straight away, no rough running, perfect tick over.

Does this point to air getting in the fuel system?

Will ask mechanic to change injector seals and washers tomorrow when I see him after work.

Light at the end of the tunnel........................????

Discosingo71 said:

Last update of the day! Just been out and tried this:

• Turned ignition on and left for 3-4 mins, could hear fuel pump whirring (not noisy).
• Waited till it stopped. Pumped gas pedal 10 times (engine management light started flashing) - this is all with ignition on.
• Pump started priming again - waited till it stopped.
• Turned key to start...............fired up straight away, no rough running, perfect tick over.

Does this point to air getting in the fuel system?

Will ask mechanic to change injector seals and washers tomorrow when I see him after work.

Light at the end of the tunnel........................????

Click to expand...

it does, i tmentioned trying the priming procedure last week:doh:

johnlad said:

it does, i tmentioned trying the priming procedure last week:doh:

Click to expand...

Yes you did suggest doing that on Friday John, and if I did I would of found out what I did tonight! :doh: Sorry for not taking up your advice!

Will try the fuel purging process again in the morning, see if it starts again no problem like tonight. If so, will convey my findings to the mechanic.

Will report back tomorrow.

johnlad said:

53 plate is a late 2003 model

Click to expand...

sorry then....but be happy the late 2003 models have reliable ECM's

Discosingo71 said:

Yes you did suggest doing that on Friday John, and if I did I would of found out what I did tonight! :doh: Sorry for not taking up your advice!

Will try the fuel purging process again in the morning, see if it starts again no problem like tonight. If so, will convey my findings to the mechanic.

Will report back tomorrow.

Click to expand...

Well the problem is getting worse. Started ok this morning after the fuel purging process, although ran rough all the way to work.

Did the same fuel purging prior to starting it to go home (from cold) and was an absolute pig to start. Took 20 mins to start, even then it was as rough as a bears ar#e! Chugged all the way to where my mechanic lives, pulled up outside his workshop, turned off and re-started..............sweet as a nut. WTF is going on!!!

Its in all day tomorrow so lets see what my mechanic finds! Hopefully whatever it is is simple to fix and more importantly cheap!

Discosingo71 said:

Well the problem is getting worse. Started ok this morning after the fuel purging process, although ran rough all the way to work.

Did the same fuel purging prior to starting it to go home (from cold) and was an absolute pig to start. Took 20 mins to start, even then it was as rough as a bears ar#e! Chugged all the way to where my mechanic lives, pulled up outside his workshop, turned off and re-started..............sweet as a nut. WTF is going on!!!

Its in all day tomorrow so lets see what my mechanic finds! Hopefully whatever it is is simple to fix and more importantly cheap!

Click to expand...

Hopefully last post!

Picked Disco up tonight.................all ok! The mechanic, working on the logic that it was running fine before he replaced the "oily" injector loom, changed it again for another genuine LR loom. Didn't adjust / change / clean anything else. Low and behold it now runs like it should, starts from cold, no rough running, no roughness or "mis firing".

The mechanic noted the fault codes when he plugged in prior to changing the loom. All the codes were "logged":

0124 Injector 2 Output Drive Peak Charge Too Long Fault.
0136 Injector 2 Output Drive Open Circuit Detected
0139 Injector 5 Output Drive Open Circuit Detected

The real test will be tomorrow morning when the Disco has been stood all night in the cold. Here's hoping..............................:laugh: