Permanent fault Needle lift sensor

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NiSk
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Permanent fault Needle lift sensor

Post by NiSk »

That's what it said on the workshop's diagnostic computer when they tested my '98 XM 2.5TD.
Does anyone know how to proceed with hands-on fault finding?
Can one measure a resistance across the injector connector and does anyone know where the signal enters the EECU so that I can check for open circuit in the cables?
If it comes down to the injector itself, is it possible to repair (at a diesel specialist of course) or is a new/replacement injector the only course?

//NiSk
'85 BX 16TRS, '91 XM injection 241,000 km (company car), '93 XM TD12 (515,000 km), '98 XM 2.5TD Break (320,000 km)
Richard Gallagher
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Post by Richard Gallagher »

I've had this fault on my TD Xantia from new, it causes the engine management light to briefly illuminate and generally log the fault in the ECU.

I returned the car under warranty on numerous occaisions with the dealer soldering the wire connection, then fitting a new needle lift injector (£148 IIRC 9 years ago) the list went on and on. At the end of it the fault still occurs from time to time (always when under a trailing throttle from high speed) although now less frequently.

My advice is that provided the car still runs OK then ignore it, otherwise if you have a similar experience to me, you spend a fortune in both time and money yet never find a solution.
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NiSk
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Post by NiSk »

Unfortunately, it won't get through the MOT equivalent with a glaring yellow engine electronics warning light on. And it does effect the injection timing (noticeably) at higher revs.
I have been told by someone on the Swedish Citroën forum that the sensor is a coil and should have resistance - mine has infinity so its dead.
Can anyone else confirm that there is a resistance across the pins of the needle lift sensor before I shell out good money on a (very expensive) new one?

//NiSk
'85 BX 16TRS, '91 XM injection 241,000 km (company car), '93 XM TD12 (515,000 km), '98 XM 2.5TD Break (320,000 km)
jeremy
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Post by jeremy »

There may be some information on this site. I recall a long threads concerning a Synergy or something with loss of power and noise - which eventually turned out to be an ECU blown by a loose earth lead. Extensive discussion on this injector there.
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AndersDK
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Post by AndersDK »

From the XM manual :

Bosch VP36 MSA11 (DK5) fuel injection : Needle lift sensor.

The sensor is integrated into injector carrier no. 3 (cylinder 3).
From this sensor the exact beginning of injection is determined by the ECU, and any injection advance is calculated from this. The sensor is an inductive type, sensing the needle core movement inside the sensor coil, inducing a current output signal to the ECU.
A defective sensor (missing sensor signal) will set faultcode 65 as a serious hard failure, and force the ECU into emergency mode.

Diagnostics :
Sensor connected, ignition on : Approx 3.5V feed to sensor from ECU should be found on the sensor wire pair.
Sensor DISconnected, ignition OFF : 100 ohms +/- 10 ohms at 20degC across the sensor wire pair.
Last edited by AndersDK on 21 Nov 2006, 15:53, edited 1 time in total.
Anders (DK) - '90 BX16Image
NiSk
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Post by NiSk »

THANK YOU ANDERS!

Just what I needed to know!
So my sensor is blown, or the short cable is O/C.
I'll try cutting it short to see if that is the problem. Otherwise i have located one at a breakers for 700 SEK.

//NiSk
'85 BX 16TRS, '91 XM injection 241,000 km (company car), '93 XM TD12 (515,000 km), '98 XM 2.5TD Break (320,000 km)
NiSk
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Post by NiSk »

Hi Again ANDERS,

Where did you get this vital information about the DK5 engine?
I've only been able to find a few small sections of Citroen information, mainly the timing gears, balance shafts, and general info about the injection system (XM 146-8).
I would dearly like to get my hands on the rest!

//NiSk
'85 BX 16TRS, '91 XM injection 241,000 km (company car), '93 XM TD12 (515,000 km), '98 XM 2.5TD Break (320,000 km)
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Post by AndersDK »

Please contact NOZ on http://club-xm.com/forum2/index.php?act=idx

He can deliver a complete XM manual (english language) on CD covering all XM's upto and including '95 models. Includes the DK5ATE diesel and the V6 petrol versions.
An impressive manual in pdf format with 1750 pages in the document :shock:
He may even have an updated version covering later models as well.
Anders (DK) - '90 BX16Image
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Problem solved and a really nice car again!

Post by NiSk »

Thanks to Anders DK, I fathomed out that the feed from the needle lift sensor was kaput. After searching through all the on-line car breakers without any luck, i suddenly remembered that Peugeot fitted the same engine to the 605 (the 2.5 td DK5). And yes, someone actually had one! And it was all mine for the measly price of £33 incl. post and COD!

Fitted it today and it was like a dream - oodles of power without hacking and poor starting! She's back like she was when i bought her!

Even sailed through the MOT equiv. this p.m. with less than half the permitted smoke level!

So - there's another fault to think of it your electronically controlled IDI diesels being a bitch.

//NiSk
'85 BX 16TRS, '91 XM injection 241,000 km (company car), '93 XM TD12 (515,000 km), '98 XM 2.5TD Break (320,000 km)
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