TD5 clutch switch

Recently, I had to have the clutch master cylinder on my 2004 TD5 Defender
changed under warranty, due to a fluid leak. Since then (6 weeks), I have
had two occasions when the engine has run unevenly and jerkily at highway
speeds. In the most recent example (last Wednesday), I was driving in the
country, and the engine was running quite badly for about 50 Km, until the
orange engine warning light came on, and I lost throttle control. I checked
for obviously loose plugs etc., and remembering the clutch master cylinder
change, unplugged the clutch switch.

All was back to normal after restarting, and since then, the car has run
faultlessly.

My question is, could intermittent opening and closing of the clutch switch
contacts, while driving, cause engine hesitation, and the warning light? It
does seem unlikely, but any information would be appreciated.

Cheers,

Graeme Evans
03 9318 0690(H), 0419 880371(B), 03 9318 0893(Fax)
E-mail: [email protected]

Graeme Evans wrote:

|| Recently, I had to have the clutch master cylinder on my 2004 TD5
|| Defender changed under warranty, due to a fluid leak. Since then (6
|| weeks), I have had two occasions when the engine has run unevenly
|| and jerkily at highway speeds. In the most recent example (last
|| Wednesday), I was driving in the country, and the engine was running
|| quite badly for about 50 Km, until the orange engine warning light
|| came on, and I lost throttle control. I checked for obviously loose
|| plugs etc., and remembering the clutch master cylinder change,
|| unplugged the clutch switch.
||
|| All was back to normal after restarting, and since then, the car has
|| run faultlessly.
||
|| My question is, could intermittent opening and closing of the clutch
|| switch contacts, while driving, cause engine hesitation, and the
|| warning light? It does seem unlikely, but any information would be
|| appreciated.

ISTR the clutch switch sends signals to the ECU for the anti-shunt feature,
which temporarily reduces fuelling when you operate the clutch to make for
smoother gear changes. If the clutch switch is duff and sending the wrong
signals, this might explain why you're getting problems with power, warning
lights etc.

BICBVVW.

--
Rich
==============================

Take out the obvious to email me.

"Richard Brookman" <[email protected]> wrote in
message news:[email protected]...
> Graeme Evans wrote:
>
> || Recently, I had to have the clutch master cylinder on my 2004 TD5
> || Defender changed under warranty, due to a fluid leak. Since then (6
> || weeks), I have had two occasions when the engine has run unevenly
> || and jerkily at highway speeds. In the most recent example (last
> || Wednesday), I was driving in the country, and the engine was running
> || quite badly for about 50 Km, until the orange engine warning light
> || came on, and I lost throttle control. I checked for obviously loose
> || plugs etc., and remembering the clutch master cylinder change,
> || unplugged the clutch switch.
> ||
> || All was back to normal after restarting, and since then, the car has
> || run faultlessly.
> ||
> || My question is, could intermittent opening and closing of the clutch
> || switch contacts, while driving, cause engine hesitation, and the
> || warning light? It does seem unlikely, but any information would be
> || appreciated.
>
> ISTR the clutch switch sends signals to the ECU for the anti-shunt
feature,
> which temporarily reduces fuelling when you operate the clutch to make for
> smoother gear changes. If the clutch switch is duff and sending the wrong
> signals, this might explain why you're getting problems with power,
warning
> lights etc.
>

This is probably the same switch/algorithm which caused the lack of power
when pulling away in early DII's. Busy junction, gap appears, try to go and
despite having your hoof flat on the the floor on the accelerator pedal you
would chug sedately out into the flow at little more than idle. And then
the computer would suddenly say "Ok, he really does mean go" and you'd blast
off with acceleration that would have impressed Captain Kirk, only to have
to tread all over the stop button again because you were now travelling too
fast for the traffic stream you'd just pulled out into. Computer
programmers, pah!

Steve

Steve wrote:

|| "Richard Brookman" <[email protected]> wrote
|| in message news:[email protected]...
||| Graeme Evans wrote:
|||
||||| Recently, I had to have the clutch master cylinder on my 2004 TD5
||||| Defender changed under warranty, due to a fluid leak. Since then
||||| (6 weeks), I have had two occasions when the engine has run
||||| unevenly and jerkily at highway speeds. In the most recent
||||| example (last Wednesday), I was driving in the country, and the
||||| engine was running quite badly for about 50 Km, until the orange
||||| engine warning light came on, and I lost throttle control. I
||||| checked for obviously loose plugs etc., and remembering the
||||| clutch master cylinder change, unplugged the clutch switch.
|||||
||||| All was back to normal after restarting, and since then, the car
||||| has run faultlessly.
|||||
||||| My question is, could intermittent opening and closing of the
||||| clutch switch contacts, while driving, cause engine hesitation,
||||| and the warning light? It does seem unlikely, but any information
||||| would be appreciated.
|||
||| ISTR the clutch switch sends signals to the ECU for the anti-shunt
||| feature, which temporarily reduces fuelling when you operate the
||| clutch to make for smoother gear changes. If the clutch switch is
||| duff and sending the wrong signals, this might explain why you're
||| getting problems with power, warning lights etc.
|||
||
|| This is probably the same switch/algorithm which caused the lack of
|| power when pulling away in early DII's. Busy junction, gap appears,
|| try to go and despite having your hoof flat on the the floor on the
|| accelerator pedal you would chug sedately out into the flow at
|| little more than idle. And then the computer would suddenly say
|| "Ok, he really does mean go" and you'd blast off with acceleration
|| that would have impressed Captain Kirk, only to have to tread all
|| over the stop button again because you were now travelling too fast
|| for the traffic stream you'd just pulled out into. Computer
|| programmers, pah!
||
|| Steve

Yup, that's the one!

The upside of it was the anti-stall feature that *increased* the fuelling if
it detected a load reducing the idle speed (eg extra load on the alt, or
starting the aircon). It made crawling in traffic a doddle, as you could do
it all with just the clutch, as long as you weren't too brutal.

--
Rich
==============================

Take out the obvious to email me.

On Sat, 7 Oct 2006 12:44:15 +0100, Richard Brookman wrote:

>|| This is probably the same switch/algorithm which caused the lack of
>|| power when pulling away in early DII's. Busy junction, gap appears,
>|| try to go and despite having your hoof flat on the the floor on the
>|| accelerator pedal you would chug sedately out into the flow at
>|| little more than idle. And then the computer would suddenly say
>|| "Ok, he really does mean go" and you'd blast off with acceleration
>|| that would have impressed Captain Kirk, ...
>
> Yup, that's the one!

Yup, it's got me a few times. I've always put it down to turbo lag rather
than the fly by wire nature of the engine though. I generally just wait
for a bigger gap, my boy racer days are a few years back.

I did have to take off a bit quick the other night though to get across
the traffic on the A69, I did remember to wind the revs up to 2,000 or so
before letting up the clutch and off she went with none of that
hesitation, much to the surprise of No.1 Son (age 6) in the back who
accused me of speeding and I was lucky that there wasn't a Police car
about...

> The upside of it was the anti-stall feature that *increased* the
> fuelling if it detected a load reducing the idle speed (eg extra load
> on the alt, or starting the aircon). It made crawling in traffic a
> doddle, as you could do it all with just the clutch, as long as you
> weren't too brutal.

Yup, use that all the time when slowly manouvering or in traffic. Pick a
suitable gear for the speed you want to pootle at and away you go.

None of this helps with the OPs problem but I have noticed that mine
occasionaly goes a but lumpy for a few seconds when just driving along.
Where is this switch again?

--
Cheers [email protected]
Dave. pam is missing e-mail

> The upside of it was the anti-stall feature that *increased* the fuelling
if
> it detected a load reducing the idle speed (eg extra load on the alt, or
> starting the aircon). It made crawling in traffic a doddle, as you could
do
> it all with just the clutch, as long as you weren't too brutal.

While we're on the topic, what does the throttle position sensor do on a
300Tdi
Disco?
I've been playing with the diesel pump settings with a good deal of success
but would like to understand a bit more.
TonyB