DK5 Engine - Injection System, TDi vs HDi

[noz]

Hi all,

Does anyone know if the DK5 engine which was fitted to several other vehicles (Fiat Ducato, Citroen C25, Jumper, Boxer, Peugeot 605 to name but a few) was ever fitted with anything other than TDi ? i.e. did any other manufacturer fit out the engine with an HDi system?

Expecting the answer to the above question to be no, does anyone know of a 2.5 diesel engine which is HDi of which the injection system would serve as a suitable donor for transplant?

That should get the juices flowing.

cheers

noz

[xmexclusive]

Hi Noz

Only the XM and Pug 605 got the DK5 engine.
All the others got the DJ5 series engines of which there were at least 4 versions.
None of these were rated as high as the DK5 and most were without turbo.
Will look out the details but from memory none were HDi.
I looked through them a few years ago as a potential source of DK5 spares.
Was very surprised to see how little was common.
For example only some of the heads and pistons were common to the DK5.

Relay:
DJ5-T9A - Comp 24:1 - 86 HP - Pump Bosch 534 VE 4/9 F 2175 R504 - Inj KCE30S5.
DJ5T-T8A - Comp 21:1 - 103 HP - Pump Lucas DPC 0678444B.

John

This post has been edited by xmexclusive on September 06, 2012 10:51 pm

[noz]

Hi John,

Thanks very much for the info. Very well informed as usual. The reason for asking was twofold. 1. a transplanted HDi system complete with Lambda sensor would almost certainly improve the fuel economy of the engine and 2. Any HDi ECU will be programmable for the purposes of installing a MAP tailored towards fuel efficiency.

It was just a shame that the last 2.5TD XMs were not fitted with Lambda sensors to meet the L3 emissions. Instead, they fitted the throttle plate and enhanced EGR valve. The Lambda sensor would have been cheaper. I'm just thinking as I write this that I might get in touch with Bosch to see if the ECU is capable of accepting a Lambda sensor one one of the unused channels.

The beauty of having the Lambda sensor is that it is the only feedback mechanism used on car fuel injection systems. All other devices are feedforward devices. i.e. the quantity of fuel and the BTDC timing are determined by a series of sensed values compared to a lookup table (MAP). If something changes in the engine as it gets older then the MAP value is no longer accurate but the engine has no way of knowing that. When the Lambda sensor is fitted it tells the ECU exactly what's happening including all of the changes the engine goes through as it gets older. As long as the values required to make the Lambda sensor happy are within the respective strokes of the injection quantity motor and the timing motor then the engine will run as sweetly as the day it was made. That's why, if an HDi system incorporating a Lambda sensor was retrofitted, then even if it was not meant for that engine then the Lambda sensor would correct the error. this assumes of course that the HDi was chosen from a vehicle of roughly the same engine size so that the injector nozzles were of the correct orifices.

Anyhow, food for thought. When I get 5 min I need to find a simple way of creating a shortlist of 2.5l diesel vehicles which have HDi. A Parkers guid or similar might be the way to do that unless anyone has any better (on-line) ideas.

cheers
noz

[xmexclusive]

Hi Noz

I am on the look out for a final drive to stretch the 2.5 gears by about 10%.
I think that would improve the fuel consumption.

John

[kenhall1202]

Hi Noz,

A lambda sensor on a diesel engine?? never heard of that application before.
Measuring the oxygen content of diesel exhaust gases would not be of much use as an excess of oxygen, over that required for combustion, is normally used.

Temperature / pressure probes across the catalyst and a particle filter, complex EGR systems and fuel additive systems appear to be the norm for some Citroen HDI diesels. Based on my own expensive experience with a 2.0HDI C4 I would suggest avoiding this type of engine like the plague**.

Ken

PS **Also any engine using a dual mass flywheel / clutch system.

This post has been edited by kenhall1202 on September 13, 2012 12:26 pm

[noz]

Ken,

Doh . Of course you are correct. I didn't stop to think of that subtlety. That's what I get for posting past bedtime. Thank you for that correction. Please don't tell anyone.....

noz

[noz]

Ken,

Maybe I wasn't so drunk after all:
http://www.lambdapower.co.uk/TechNotes/Tech-14.asp

Diesel Lambda sensors

This super-fine control of mixture strength allows Lambda control to be possible for these common-rail systems, and from about 2005 onwards this has become the norm. Motivating all these innovations are EU emissions regulations, which are becoming ever more stringent for Diesel cars after an initial phase of being allowed to lag behind the equivalent petrol-engine regulations.

Diesels are by nature lean burn engines, so require a wideband lambda sensor that can detect A/F ratios over a very large range. Silicone compounds are added to diesel fuel to ease transportation and for their anti-foaming properties, which poisons the lambda sensor over time, but additional measures are taken in the design of diesel lambda sensors in order to combat or lessen this problem.

[kenhall1202]

Hi Noz,

Well you live and learn! Sounds like another potential MOT requirement to be met along with the existing crude smoke test for current diesels which are having to meet ever more stringent emission limits.

In my sad experience of recent HDI diesel engines the technology is advancing at a rate much faster than the ability of the average garage technician to accurately and efficiently diagnose problems.

Ken

[nightmare]

citroen do a 2.2 hdi and a 2.7 hdi C5 & C6.

HTH