fil2462
Member Since: 25 Nov 2020
Location: Isle of Skye
Posts: 1
 
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| Tdci 2.4 Idle-Seeking and eventually cutting out: SOLVED! | |
After some great advice sourced on here, I promised I'd do a quick write up in case it helps anyone else...
VEHICLE:
Defender 110 Tdci 2.4 Puma 2007. Very low mileage (35k at this point)
SYMPTOMS:
The initial symptoms were the idling 'seeking/wobbling' on occasion around the 1000rpm. Sometimes it would very briefly drop to around 700rpm, then return to normal with no other worries. This started sporadically, so pretty much ignored as 'maybe poor fuel' at first, but over the following few weeks/months gradually became very noticeable and more regular.
Next stage was cutting out. Once or twice (only every few weeks) it would wobble at idle - only at idle- then cut out. She started up again and ran without issue, but this was starting to really concern me as it showed it getting progressivly worse. A good friend told me it may have been my alarm/immobiliser and to consider removing that, and also that it may be an earth connection. All earths checked, removed, cleaned up - but symptoms persisted.
An oil and fuel filter service didn't change anything, neither did MAF and MAP sensor replacements.
After getting slowly but steadily worse, and my confidence in the 110 dropping, then came the dreaded cutting out whilst driving- this was a new one. This happened a few times over a week or two before it eventually gave up the ghost and refused to start. It would crank and turn over but as if it had no fuel. Fuel delivery seemed logical but a replacement Fuel Rail High Pressure sensor (LR part number LR009732 or 55PP05-01 MYA) had no effect either.
A very knowledgeable guy locally pointed me in the direction of the PCV (VCV?) valve, so one was purchased (LR part number LR009837) and fitted. Fiddly, skin-off-the-knuckle type of job but not too technical to replace. It started, but idling was terrible and not the complete fix. I did read about having the car 'learn' the PCV with a full diagnostics setup, but was informed this wasn't required (more on that later).
The fact this had an effect, but not complete fix, showed we were onto something with the fuel rail...
Next came the Fuel Pressure Relief (release) Valve LR006866. This was a bit of a nightmare to replace - I was told it needed real force to tighten up, and by God did it ever. No matter how much force it continued to spray diesel when turning over, and I even replaced this part 3 times thinking I had a dodgy part.
I ended up using Loctite 577 (sealant for fuel lines) which was quite expensive online (around £35, but found a local engineering company that had one for £20). This did the job and it finally stopped spraying diesel everywhere when running. However, it was knocking away now. ***NOTE* Do not lose the internal copper washer! It may come out of the fuel rail (it's deep inside and a little fingertip job to get out) but they're a nightmare to source. I got mine out and 'annealed' it. Easy enough and worked a treat:
We then had the injectors tested at a diesel engine craft place. Showed injectors 2/3 were not performing, so they were replaced just in case. Still ran poorly, so we replaced the fuel line sensor and pressure relief valve again (thinking they may have been poor quality parts, even though one was Denso and the other 'genuine'). No joy.
Each time, the starting, ticker, or running would change. Sometimes for the better - but obviously not right - sometimes for the worse. Hair pulling time.
We got to the point where we asked a local expert - and good guy - to take it away and start investigating. After a week or so he had opted to replace the PCV (VCV) again (assuming bad part) and tried the diagnostics 'learning' of the PCV. Amazingly, it worked.
He said, although he had never seen this before, the diagnostics took over the car - raising the RPM to 3000, lowering, settling, raising and lowering for quite some time. Eventually it settled, idled and sounded great - the computer said it was 'complete'.
Joy of joys! 
Now, to summarise (and this may ask more questions than it answers): I do not know if it was a faulty PCV all along and it required learning after all, or whether it was a sequence of failures in my fuel line. the car had genuinely only done 35k by this point, and even had the factory stickers still on the chassis. But stranger things have happened at sea.
In hindsight, I can only advise replacing the PCV and insist on having a diagnostics plugged in to try and 'learn/syncronise' it. Failing that, replace the fuel line parts (sensor, pressure relief valve) and check the injectors.
NOTE:
I found that the fuel rail valves, sensor, PCV/VCV and Fuel Pressure Relief are all the same as the 2.4 Tdci Transit ford ones. Search their part numbers as there's potentially money to be saved when searching for replacements!
Given the results of the injector tests and subsequent problems, I can only assume that two of the injectors were starting to fail, putting increased pressure on the fuel delivery. This, in turn, may have caused further failure of the PCV/pressure release valve (one time use apparently - when it pops its finished). I either had one or two dodgy parts (some parts ranged from £25 to £200 for the same thing so can be hit-and-miss I guess). The fuel rail (part number LR006865) wasn't required to be replaced, and I also believe these are the same on the equivalent Ford Transit too.
But eventually, it was solved.
Any questions I'm happy to help (please remember, im only a home amateur though)!
Last edited by fil2462 on 17th Nov 2023 10:41am. Edited 2 times in total
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17th Nov 2023 9:10am
Jumped ship to reliability - Mitsubishi L200
