In message , Jim GM4DHJ ...
writes

"Charles Hope" wrote in message
. ..
In article , Jim GM4DHJ ...
wrote:

"Tim Streater" wrote in message
.. .
In article , Jim GM4DHJ ...
wrote:

"Broadback" wrote in message
...
I have decided to change to premium petrol for my car. Is this OK for
2 stroke garden equipment, or should I always make sure I use the
standard petrol?

has your fuel gauge been buggered up by supermarket petrol as well ?
.....

Woss wrong with supermarket fuel? We never buy anything else (diesel
C4).

buggered up my old merc fuel gauge.....few tanks of shell and BP premium
sorted it out ......

and where do you think the supermarkets get their fuel? some backstreet
arab trader?


most only do 95 oct .....

Pretty sure all the supermarkets around here to Premium fuel as well
--
Chris French

In article , Jim GM4DHJ ...
wrote:

"Tim Streater" wrote in message
.. .
In article , Jim GM4DHJ ...
wrote:

"Tim Streater" wrote in message
...
In article , Jim GM4DHJ ...
wrote:

"Charles Hope" wrote in message
...
In article , Jim GM4DHJ ...
wrote:

hope you have a diesel car then ....

I do and have done so for about 25 years

horrible things ...

In what way?

filthy smoke, dual mass flywheels, turbos to get any performance,
particulate filters etc etc....

I do see filthy smoke taxis and other small commercial vehicles from
time to time, I assume it's because they haven't bothered to maintain
them although how they get away with that vis-a-vis the MOT is a good
question.

I just had my particulate filter changed at 75k miles.

you don't need to do that on a petrol...and don't get me started on
rubber cam belt diesels .......

you don't have to change the plugs on diesels, nor, when I went diesel,
check the points or worry about a distributor failing. That happend to me
twice with a petrol engined car.

On Wed, 22 Jul 2015 20:15:16 +0100, Charles Hope wrote:

you don't have to change the plugs on diesels, nor, when I went diesel,
check the points or worry about a distributor failing. That happend to
me twice with a petrol engined car.

I doubt there's a single car been built since about 1990 with points -
and not many from the previous 5-10yrs.

I doubt there's a single car been built in the last 15 years with a
distributor - and they failed VERY infrequently.

If you think you don't have to change the plugs on a diesel, you've never
had the shenanigans of glow plugs failing. Spark plugs on petrols are
often 100k intervals these days, btw.

On Wed, 22 Jul 2015 20:08:41 +0100, Chris French wrote:

Woss wrong with supermarket fuel? We never buy anything else (diesel
C4).

buggered up my old merc fuel gauge.....few tanks of shell and BP premium
sorted it out ......

Says more about your Merc then i think.

I've only ever used standard fuel (petrol or diesel) supermarkets, oil
company garages where ever, never had fuel gaugae problems on any of our
cars

I struggle to imagine how a fuel gauge sender could be affected by fuel,
short of the float somehow dissolving, and that ain't going to fix itself.

In article ,
Adrian wrote:
On Wed, 22 Jul 2015 20:08:41 +0100, Chris French wrote:

Woss wrong with supermarket fuel? We never buy anything else (diesel
C4).

buggered up my old merc fuel gauge.....few tanks of shell and BP premium
sorted it out ......

Says more about your Merc then i think.

I've only ever used standard fuel (petrol or diesel) supermarkets, oil
company garages where ever, never had fuel gaugae problems on any of our
cars

I struggle to imagine how a fuel gauge sender could be affected by fuel,
short of the float somehow dissolving, and that ain't going to fix itself.

It could "gum up".

On 22/07/15 19:37, Jim GM4DHJ ... wrote:
"Tim Streater" wrote in message
.. .
In article , Jim GM4DHJ ...
wrote:

"Tim Streater" wrote in message
.. .
In article , Jim GM4DHJ ...
wrote:

"Charles Hope" wrote in message
...
In article , Jim GM4DHJ ...
wrote:

hope you have a diesel car then ....

I do and have done so for about 25 years

horrible things ...

In what way?

filthy smoke, dual mass flywheels, turbos to get any performance,
particulate filters etc etc....

I do see filthy smoke taxis and other small commercial vehicles from
time to time, I assume it's because they haven't bothered to maintain
them although how they get away with that vis-a-vis the MOT is a good
question.

I just had my particulate filter changed at 75k miles.

you don't need to do that on a petrol...

no, but you will have changed the plugs 5 times in that period.


and don't get me started on rubber
cam belt diesels .......




--
New Socialism consists essentially in being seen to have your heart in
the right place whilst your head is in the clouds and your hand is in
someone else's pocket.

On 22/07/15 20:29, Adrian wrote:
On Wed, 22 Jul 2015 20:15:16 +0100, Charles Hope wrote:

you don't have to change the plugs on diesels, nor, when I went diesel,
check the points or worry about a distributor failing. That happend to
me twice with a petrol engined car.

I doubt there's a single car been built since about 1990 with points -
and not many from the previous 5-10yrs.

I doubt there's a single car been built in the last 15 years with a
distributor - and they failed VERY infrequently.

actually a few.


If you think you don't have to change the plugs on a diesel, you've never
had the shenanigans of glow plugs failing. Spark plugs on petrols are
often 100k intervals these days, btw.


as are glo plugs.


--
New Socialism consists essentially in being seen to have your heart in
the right place whilst your head is in the clouds and your hand is in
someone else's pocket.

"Charles Hope" wrote in message
...
In article , Jim GM4DHJ ...
wrote:

"Tim Streater" wrote in message
.. .
In article , Jim GM4DHJ ...
wrote:

"Tim Streater" wrote in message
...
In article , Jim GM4DHJ ...
wrote:

"Charles Hope" wrote in message
...
In article , Jim GM4DHJ ...
wrote:

hope you have a diesel car then ....

I do and have done so for about 25 years

horrible things ...

In what way?

filthy smoke, dual mass flywheels, turbos to get any performance,
particulate filters etc etc....

I do see filthy smoke taxis and other small commercial vehicles from
time to time, I assume it's because they haven't bothered to maintain
them although how they get away with that vis-a-vis the MOT is a good
question.

I just had my particulate filter changed at 75k miles.

you don't need to do that on a petrol...and don't get me started on
rubber cam belt diesels .......

you don't have to change the plugs on diesels, nor, when I went diesel,
check the points or worry about a distributor failing. That happend to me
twice with a petrol engined car.


I took out the plugs on the merc at 170k for the first time and they were
fine....modern petrol cars don't have distributors, points or even plug
leads ......

"Chris French" wrote in message
...
In message , Jim GM4DHJ ...
writes

"Charles Hope" wrote in message
.. .
In article , Jim GM4DHJ ...
wrote:

"Tim Streater" wrote in message
.. .
In article , Jim GM4DHJ ...
wrote:

"Broadback" wrote in message
...
I have decided to change to premium petrol for my car. Is this OK
for
2 stroke garden equipment, or should I always make sure I use the
standard petrol?

has your fuel gauge been buggered up by supermarket petrol as well ?
.....

Woss wrong with supermarket fuel? We never buy anything else (diesel
C4).

buggered up my old merc fuel gauge.....few tanks of shell and BP
premium
sorted it out ......

and where do you think the supermarkets get their fuel? some backstreet
arab trader?


most only do 95 oct .....

Pretty sure all the supermarkets around here to Premium fuel as well
Chris French


Em I tell a lie...I tell a lie....just been to tesco they do have momentum
99 ron ....sorry .....never noticed it before....

"Chris French" wrote in message
...
In message , Jim GM4DHJ ...
writes

"Tim Streater" wrote in message
...
In article , Jim GM4DHJ ...
wrote:

"Broadback" wrote in message
...
I have decided to change to premium petrol for my car. Is this OK for 2
stroke garden equipment, or should I always make sure I use the
standard
petrol?

has your fuel gauge been buggered up by supermarket petrol as well ?
.....

Woss wrong with supermarket fuel? We never buy anything else (diesel
C4).

buggered up my old merc fuel gauge.....few tanks of shell and BP premium
sorted it out ......

Says more about your Merc then i think.

I've only ever used standard fuel (petrol or diesel) supermarkets, oil
company garages where ever, never had fuel gaugae problems on any of our
cars
Chris French


yes they should never have went in with Chrysler...my 190e was like a brick
compared to this c180 w202

"Adrian" wrote in message
...
On Wed, 22 Jul 2015 20:08:41 +0100, Chris French wrote:

Woss wrong with supermarket fuel? We never buy anything else (diesel
C4).

buggered up my old merc fuel gauge.....few tanks of shell and BP premium
sorted it out ......

Says more about your Merc then i think.

I've only ever used standard fuel (petrol or diesel) supermarkets, oil
company garages where ever, never had fuel gaugae problems on any of our
cars

I struggle to imagine how a fuel gauge sender could be affected by fuel,
short of the float somehow dissolving, and that ain't going to fix itself.

the variable resistor(s) gums up and gives you weird OHM readings at the
gauge...

On Wed, 22 Jul 2015 20:37:32 +0100, Charles Hope wrote:

I struggle to imagine how a fuel gauge sender could be affected by
fuel, short of the float somehow dissolving, and that ain't going to
fix itself.

It could "gum up".

A LOOOOOOOOOONG while after the pump, filter, injectors would gum up.

"The Natural Philosopher" wrote in message
...
On 22/07/15 19:37, Jim GM4DHJ ... wrote:
"Tim Streater" wrote in message
.. .
In article , Jim GM4DHJ ...
wrote:

"Tim Streater" wrote in message
.. .
In article , Jim GM4DHJ ...
wrote:

"Charles Hope" wrote in message
...
In article , Jim GM4DHJ ...
wrote:

hope you have a diesel car then ....

I do and have done so for about 25 years

horrible things ...

In what way?

filthy smoke, dual mass flywheels, turbos to get any performance,
particulate filters etc etc....

I do see filthy smoke taxis and other small commercial vehicles from
time to time, I assume it's because they haven't bothered to maintain
them although how they get away with that vis-a-vis the MOT is a good
question.

I just had my particulate filter changed at 75k miles.

you don't need to do that on a petrol...

no, but you will have changed the plugs 5 times in that period.

Not with modern computer controlled cars.

and don't get me started on rubber
cam belt diesels .......

On 7/22/2015 7:59 AM, Broadback wrote:
I have decided to change to premium petrol for my car. Is this OK for 2
stroke garden equipment, or should I always make sure I use the standard
petrol?

I have always used super in my tools and never had a problem... (never
had a problem with stale petrol either)

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Broadback wrote:

I have decided to change to premium petrol for my car. Is this OK for 2
stroke garden equipment, or should I always make sure I use the standard
petrol?

im not sure if this is still valid info
but some €œpremium€� or €œsuper€� unleaded does not contain ethanol
which is a good thing as far as 2 strokes go IMHO
bottom of page
http://www.groups.tr-register.co.uk/...ol-update.html

On Wed, 22 Jul 2015 22:23:14 +0100
Tim Streater wrote:

In article , Jim GM4DHJ ...
wrote:

I took out the plugs on the merc at 170k for the first time and they
were fine....modern petrol cars don't have distributors, points or
even plug leads

So hows the spark generated and timed, and how do the volts get to the
plug? Magic?


Each plug has its own coil, which is fed with low volts, and sits
directly on top of the plug. All controlled by an ECU.
https://www.youtube.com/watch?v=8Lr6teZ1S_U

--
Davey.

"Tim Streater" wrote in message
.. .
In article , Jim GM4DHJ ...
wrote:

I took out the plugs on the merc at 170k for the first time and they were
fine....modern petrol cars don't have distributors, points or even plug
leads

So hows the spark generated and timed, and how do the volts get to the
plug? Magic?


camshaft and crankshaft position sensors...I have had to replace both within
the last few months.....coil packs for each cyl.....admittedly on the merc
there are very short HT leads but they are well protected from the
elements.... but on my wagon r the coil pack plugs down directly onto the
spark plugs.... yes it is magic to get rid of distributors and a stand alone
coil and HT leads...pure magic ....apart from bloody sensors going faulty
with heat after 165k miles and the engine stops...very annoying but a £17
OBD2 scanner tells you what is wrong ....

On 23/07/2015 00:14, Davey wrote:
On Wed, 22 Jul 2015 22:23:14 +0100
Tim Streater wrote:

In article , Jim GM4DHJ ...
wrote:

I took out the plugs on the merc at 170k for the first time and they
were fine....modern petrol cars don't have distributors, points or
even plug leads

So hows the spark generated and timed, and how do the volts get to the
plug? Magic?


Each plug has its own coil, which is fed with low volts, and sits
directly on top of the plug. All controlled by an ECU.
https://www.youtube.com/watch?v=8Lr6teZ1S_U


My last car had two coils(1) in one plastic block and had plug leads but
no points, etc. I haven't looked at the latest car, no reason to,
they just work.

1: On a four cylinder job you only need two coils as they generate a
spark in two cylinders at the same time, one being ready to fire and one
being at the point of being exhausted so it doesn't matter.

On 22/07/2015 16:09, Charles Hope wrote:
In article , Jim GM4DHJ ...
wrote:

"Tim Streater" wrote in message
.. .
In article , Jim GM4DHJ ...
wrote:

"Broadback" wrote in message
...
I have decided to change to premium petrol for my car. Is this OK for
2 stroke garden equipment, or should I always make sure I use the
standard petrol?

has your fuel gauge been buggered up by supermarket petrol as well ?
.....

Woss wrong with supermarket fuel? We never buy anything else (diesel
C4).

buggered up my old merc fuel gauge.....few tanks of shell and BP premium
sorted it out ......

and where do you think the supermarkets get their fuel? some backstreet
arab trader?


Close. While Tesco part owns Greenergy and get their fuel from them,
most probably still buy on the spot market, which means they go to the
cheapest supplier, many of whom you quite possibly have never heard of.
While that fuel will (usually*) comply with the statutory minimum
standards, it won't have the additives that the main line fuel companies
spend millions developing.

* A Google search throws up several hits on fuel contamination, from the
extensive contamination of Tesco, Morrsion and Asda petrol with silicon
in 2007, to a single garage where rainwater got into the fuel tanks.
Most involve supermarkets.

--
Colin Bignell

On Thu, 23 Jul 2015 00:13:07 +0100, Mark wrote:

im not sure if this is still valid info but some €œpremium€� or €œsuper€�
unleaded

Umm, "premium unleaded" and "super unleaded" are the only two petrols we
can get in the UK.

"Premium unleaded" is 95.
"Super unleaded" is 98ish.

There used to be a standard unleaded, 91, but we never got it here.

On Thu, 23 Jul 2015 00:13:07 +0100, Mark wrote:

im not sure if this is still valid info but some €œpremium€� or €œsuper€�
unleaded does not contain ethanol which is a good thing as far as 2
strokes go IMHO bottom of page
http://www.groups.tr-register.co.uk/...ol-update.html

Oh, and that link is early 2011...

On Thu, 23 Jul 2015 08:16:08 +0100, dennis@home wrote:

My last car had two coils(1) in one plastic block and had plug leads but
no points, etc. I haven't looked at the latest car, no reason to,
they just work.

1: On a four cylinder job you only need two coils as they generate a
spark in two cylinders at the same time, one being ready to fire and one
being at the point of being exhausted so it doesn't matter.

Wasted spark ignition. As fitted to every single 2cv built from 1948 to
1990...

"dennis@home" wrote in message
eb.com...
On 23/07/2015 00:14, Davey wrote:
On Wed, 22 Jul 2015 22:23:14 +0100
Tim Streater wrote:

In article , Jim GM4DHJ ...
wrote:

I took out the plugs on the merc at 170k for the first time and they
were fine....modern petrol cars don't have distributors, points or
even plug leads

So hows the spark generated and timed, and how do the volts get to the
plug? Magic?


Each plug has its own coil, which is fed with low volts, and sits
directly on top of the plug. All controlled by an ECU.
https://www.youtube.com/watch?v=8Lr6teZ1S_U


My last car had two coils(1) in one plastic block and had plug leads but
no points, etc. I haven't looked at the latest car, no reason to,
they just work.

1: On a four cylinder job you only need two coils as they generate a spark
in two cylinders at the same time, one being ready to fire and one being
at the point of being exhausted so it doesn't matter.

yes the merc is like that but the Vauxhall engined 1.2 wagon r has one per
cyl .......

"Adrian" wrote in message
...
On Thu, 23 Jul 2015 08:16:08 +0100, dennis@home wrote:

My last car had two coils(1) in one plastic block and had plug leads but
no points, etc. I haven't looked at the latest car, no reason to,
they just work.

1: On a four cylinder job you only need two coils as they generate a
spark in two cylinders at the same time, one being ready to fire and one
being at the point of being exhausted so it doesn't matter.

Wasted spark ignition. As fitted to every single 2cv built from 1948 to
1990...


....and a load of Honda motorbikes

On Thu, 23 Jul 2015 10:55:44 +0100, Tim Streater wrote:

So hows the spark generated and timed, and how do the volts get to the
plug? Magic?

Coil on plug, where there is one ignition coil per plug, built into the
plug cap. There are no HT plug leads. The spark is timed by the ECU,
which "knows" exactly where in the the Otto cycle the engine is by
counting teeth on a timing wheel on the crankshaft. It fires the
appropriate plug at the appropriate time. There is no distributor.

That Otto, he's got a lot to answer for. So it is magic after all.

All he's got to answer for is "Suck. Squeeze. Bang. Blow."

The rest is just fine detail.

On 7/23/2015 12:13 AM, Mark wrote:
Broadback wrote:

I have decided to change to premium petrol for my car. Is this OK for 2
stroke garden equipment, or should I always make sure I use the standard
petrol?

im not sure if this is still valid info
but some €œpremium€� or €œsuper€� unleaded does not contain ethanol
which is a good thing as far as 2 strokes go IMHO
bottom of page
http://www.groups.tr-register.co.uk/...ol-update.html

Might be worth noting that "premium" and "super" are not typically the
same thing. Most forecourt premium fuel is 95 RON, while super is
typically 97 to 99.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

In article , Jim GM4DHJ ... wrote:
"Charles Hope" wrote in message
. ..
Jim GM4DHJ ... wrote:

dual mass flywheels, turbos to get any performance,
particulate filters etc etc....

What's wrong with a turbo?

ask a nissan xtrail with intercooler ....

I have a diesel Nissan X-Trail which has done over 200,000 miles.
What's wrong with a turbo?

"Alan Braggins" wrote in message
...
In article , Jim GM4DHJ ... wrote:
"Charles Hope" wrote in message
.. .
Jim GM4DHJ ... wrote:

dual mass flywheels, turbos to get any performance,
particulate filters etc etc....

What's wrong with a turbo?

ask a nissan xtrail with intercooler ....

I have a diesel Nissan X-Trail which has done over 200,000 miles.
What's wrong with a turbo?

lucky lucky lucky...what about the intercooler then ? .....

"John Rumm" wrote in message
...
On 7/23/2015 12:13 AM, Mark wrote:
Broadback wrote:

I have decided to change to premium petrol for my car. Is this OK for 2
stroke garden equipment, or should I always make sure I use the standard
petrol?

im not sure if this is still valid info
but some "premium" or "super" unleaded does not contain ethanol
which is a good thing as far as 2 strokes go IMHO
bottom of page
http://www.groups.tr-register.co.uk/...ol-update.html

Might be worth noting that "premium" and "super" are not typically the
same thing. Most forecourt premium fuel is 95 RON, while super is
typically 97 to 99.


tesco momentum is 99 as I just found out yesterday.........

On Thu, 23 Jul 2015 10:37:43 +0100
"Jim GM4DHJ ..." wrote:


"Adrian" wrote in message
...
On Thu, 23 Jul 2015 08:16:08 +0100, dennis@home wrote:

My last car had two coils(1) in one plastic block and had plug
leads but no points, etc. I haven't looked at the latest car, no
reason to, they just work.

1: On a four cylinder job you only need two coils as they generate
a spark in two cylinders at the same time, one being ready to fire
and one being at the point of being exhausted so it doesn't matter.

Wasted spark ignition. As fitted to every single 2cv built from
1948 to 1990...


...and a load of Honda motorbikes



but not all modern cars, just some.

--
Davey.

Alan Braggins posted
In article , Jim GM4DHJ ... wrote:
"Charles Hope" wrote in message
.. .
Jim GM4DHJ ... wrote:

dual mass flywheels, turbos to get any performance,
particulate filters etc etc....

What's wrong with a turbo?

ask a nissan xtrail with intercooler ....

I have a diesel Nissan X-Trail which has done over 200,000 miles.
What's wrong with a turbo?


He's referring to the fairly common fault on the T31 model where the
intercooler leaks oil into the turbo, and buggers it up by overboosting
it.



--
Les

"Big Les Wade" wrote in message
...
Alan Braggins posted
In article , Jim GM4DHJ ... wrote:
"Charles Hope" wrote in message
. ..
Jim GM4DHJ ... wrote:

dual mass flywheels, turbos to get any performance,
particulate filters etc etc....

What's wrong with a turbo?

ask a nissan xtrail with intercooler ....

I have a diesel Nissan X-Trail which has done over 200,000 miles.
What's wrong with a turbo?


He's referring to the fairly common fault on the T31 model where the
intercooler leaks oil into the turbo, and buggers it up by overboosting
it.



Les


um ur

On Thu, 23 Jul 2015 10:37:43 +0100, Jim GM4DHJ ... wrote:

"Adrian" wrote in message
...
On Thu, 23 Jul 2015 08:16:08 +0100, dennis@home wrote:

My last car had two coils(1) in one plastic block and had plug leads
but no points, etc. I haven't looked at the latest car, no reason to,
they just work.

1: On a four cylinder job you only need two coils as they generate a
spark in two cylinders at the same time, one being ready to fire and
one being at the point of being exhausted so it doesn't matter.

Wasted spark ignition. As fitted to every single 2cv built from 1948 to
1990...


...and a load of Honda motorbikes

Such as my younger brother's CB160 in the early seventies, despite the
use of a '180 degree throw' crank, twin cylinder 4 stroke engine.

If you want your spark plugs to last 100 thousand miles(Km?), the only
way to achieve this is by using the "Capacitor Discharge Ignition" (CDI)
method. Using a 'transistorised' CB (as per my son's 600cc 4 cylinder
Yamaha Bandit's twin coil 'wasted spark' ignition system) just doesn't
'cut it' as far as plug life goes[1].

Using a pair of double ended ignition coils on a 4 cylinder engine in a
"Wasted Spark" system offers a relatively cheap way to avoid the expense
and liability of a single coil/distributor configuration.

However, a coil fault could cause misfiring on one *or* two cylinders
(often two if the 'coil fault' was really the CD module or transistorised
CB driving the primary of said coil).

When diagnosing such misfiring problems, it was important to know which
*two* cylinders were involved when using the classic 'detach each HT lead
in turn' to detect the 'faulty HT circuit' since you had to make sure the
'waste spark end' had a low volt drop return to chassis (usually via a
spare spark plug resting or wedged into contact with the engine cylinder
head or other such metallic parts).

If you simply detached the suspect HT lead as 'in the good old days with
coil/distributor' setups, you were likely to kill the spark on the
opposite cylinder thus disabling two cylinders at a time with no means of
identifying which of the two was the *one* failed HT circuit/sparkplug
causing the symptoms of an obvious single cylinder misfire.

The higher performance engines would have one CDI module per cylinder
which made diagnosis much easier (and the carrying of a single spare
module and spark plug much less space consuming in the roadside repair
kit that any well prepared driver would make sure to be carrying in their
car at all times).

[1] When my son was trying (and failing) to diagnose a 'mystery'
intermittent misfiring/loss of power fault on a 2nd hand Bandit he'd
recently bought last year, I got the opportunity to see the ignition
module circuit. I was rather unimpressed by the use of a high voltage
switching transistor emulation of the humble (and very much deprecated)
Contact Breaker, Kettering ignition system.

The use of a microprocessor to control the advance/retard (and dwell
time) to eliminate the mechanical bob weights system of old was
impressive but it seemed rather a shame that they'd stuck to the much
deprecated 'interrupt the primary current' of old as the means to
generate the 3 or 4 hundred volt pulse needed by the 100:1 step up ratio
coil in order to generate the 30 to 40 KV HT pulse supply to each plug.

The reason why this antiquated (albeit 'transistorised') method is
deprecated is simply on account the ignition coil not only has to act as
a 'step up transformer' it also has to provide the necessary inductance
to form a flyback voltage converter which function relies on there *not*
being any shunt loading in either the primary or (and this is the most
important bit) the secondary HT side of the coil circuit to 'suck this
flyback pulse energy out of the voltage generating pulse before it has
had a chance to reach a peak sufficient to jump the spark gap.

Leakage on the HT circuit, HT leads with cracks or other imperfections
aggravated by moisture ingress or fouled plugs, is all the loading that's
required to defeat the antiquated Kettering system (transistorised or
not).

The huge benefit of CDI, aside from a well timed single *full* equipolar
cycle hot spark at the plug points[2], was that such leakage had very
little effect on the spark voltage pulse other than a simple bit of volt
drop due to coil winding impedance. In a CDI setup, the coil primary was
going to see that 3 or 4 hundred volt pulse come hell or high water.

What happened after that was purely a matter of coil impedance volt drop
against whatever (up to a significantly larger amount of) leakage path
loadings as may be present in the HT circuit (cable leakage or plug
fouling leakage[2] or whatever).

This is important, especially in regard of allowing a harder grade of
plug to be used. The spark plugs can be allowed to run much cooler than
would otherwise be advisable in the old fashioned Kettering system if you
don't want the inevitable effects of plug electrode insulator fouling to
cause misfiring due to extensive city stop start driving conditions
preventing the plug experiencing regular bouts of higher temperature
operation to burn off such accumulations of fouling deposits during
'normal' cruising operation on motorways and open A and B roads.

In addition, the longer hotter spark allowed the rather inhomogeneous
spotty idle mixture to be adjusted closer to the ideal than the over-rich
setting normally required by the weaker spark of the Kettering system,
which helped maintain a hotter, more economical leaner burning and less
sooty mixture which mitigated the fouling effect of the cooler harder
grade plugs that were being chosen.

[2] The optimum spark pulse, despite the claims made elsewhere, is the
single full cycle (full fat, as it were) equipolar spark pulse on a 40
thou gapped plug. The single cycle equipolar pulse significantly reduces
electrical erosion on the spark plugs' electrodes, the main limiting
factor in a spark plug's service life.

The antiquated Kettering system ('transistorised' or not) generates a
spark with a considerable unipolar bias on the spark current, so much so
that this is why the LT connections on ignition coils have polarity
markings in order to make sure the (adjustable) earth electrode is the
one that erodes, leaving the centre electrode to grow an easily filed off
'pip'.

At the time when CDI was just starting to become available in the mid
70s as an upgrade kit to use the existing CB points and ignition coil,
amongst the many real benefits, the extension of plug service life from a
typical 6 to 10 thousand miles to something more like 20 to 30 thousand
miles[3] was a real 'winner' (and the reduced current/voltage at the CB
points from 4A/300 odd volts to a mere 50 to 100mA/12 to 15 volts,
removing the major cause of timing drift made this aspect a "Win, win"
situation. :-)

If you were going to "Transistorise" your ignition system, CDI left the
crappy Transistorised CB circuit for dead. The 'benefit' of the simple
transistorised CB was only a small fraction of what a CB points triggered
CDI setup had to offer (later CDI 'upgrade kits' provided an optical
triggering unit to replace the points assembly in the distributor itself
by way of an extra 'embellishment').

[3] The 100 thousand miles rating for spark plug service life seems a
little OTT to me but, in view of developments over the past 4 decades or
so since the standard spark plugs of the day, back in the 70s, could be
made to last 25 or so thousand miles in a CDI setup versus the 6 to 10
thousand miles in a 'conventional' Kettering setup, I'm willing to
believe this actually might be true (although a 100 Km life is less
stretching of credulity :-)

--
Johnny B Good

"Johnny B Good" wrote in message
...
On Thu, 23 Jul 2015 10:37:43 +0100, Jim GM4DHJ ... wrote:

"Adrian" wrote in message
...
On Thu, 23 Jul 2015 08:16:08 +0100, dennis@home wrote:

My last car had two coils(1) in one plastic block and had plug leads
but no points, etc. I haven't looked at the latest car, no reason to,
they just work.

1: On a four cylinder job you only need two coils as they generate a
spark in two cylinders at the same time, one being ready to fire and
one being at the point of being exhausted so it doesn't matter.

Wasted spark ignition. As fitted to every single 2cv built from 1948 to
1990...


...and a load of Honda motorbikes

Such as my younger brother's CB160 in the early seventies, despite the
use of a '180 degree throw' crank, twin cylinder 4 stroke engine.

Johnny B Good

or my c95 .....1966


https://www.youtube.com/watch?v=aD58uAyGQsk

On 23/07/2015 13:19, Big Les Wade wrote:
Alan Braggins posted
In article , Jim GM4DHJ ... wrote:
"Charles Hope" wrote in message
...
Jim GM4DHJ ... wrote:

dual mass flywheels, turbos to get any performance,
particulate filters etc etc....

What's wrong with a turbo?

ask a nissan xtrail with intercooler ....

I have a diesel Nissan X-Trail which has done over 200,000 miles.
What's wrong with a turbo?


He's referring to the fairly common fault on the T31 model where the
intercooler leaks oil into the turbo, and buggers it up by overboosting it.

That's a bit dumb. Intercooler should be a really simple device -
air/air radiator.

"Clive George" wrote in message
o.uk...
On 23/07/2015 13:19, Big Les Wade wrote:
Alan Braggins posted
In article , Jim GM4DHJ ... wrote:
"Charles Hope" wrote in message
...
Jim GM4DHJ ... wrote:

dual mass flywheels, turbos to get any performance,
particulate filters etc etc....

What's wrong with a turbo?

ask a nissan xtrail with intercooler ....

I have a diesel Nissan X-Trail which has done over 200,000 miles.
What's wrong with a turbo?


He's referring to the fairly common fault on the T31 model where the
intercooler leaks oil into the turbo, and buggers it up by overboosting
it.

That's a bit dumb. Intercooler should be a really simple device - air/air
radiator.


what's the repair bill for those...over £1000 ? ....

On 23/07/2015 17:53, Jim GM4DHJ ... wrote:
"Clive George" wrote in message
o.uk...
On 23/07/2015 13:19, Big Les Wade wrote:
Alan Braggins posted
In article , Jim GM4DHJ ... wrote:
"Charles Hope" wrote in message
...
Jim GM4DHJ ... wrote:

dual mass flywheels, turbos to get any performance,
particulate filters etc etc....

What's wrong with a turbo?

ask a nissan xtrail with intercooler ....

I have a diesel Nissan X-Trail which has done over 200,000 miles.
What's wrong with a turbo?


He's referring to the fairly common fault on the T31 model where the
intercooler leaks oil into the turbo, and buggers it up by overboosting
it.

That's a bit dumb. Intercooler should be a really simple device - air/air
radiator.

what's the repair bill for those...over £1000 ? ....

An intercooler like the ones I've seen with two air pipes (one in, one
out) and no more connections should be not much more than the cost of
the new part to replace. Air pipes are trivial to connect/disconnect,
the only fun might come if access is tricky, eg having the normal
radiator in the way.

110 quid + vat for mine from the first place I found.

On 22/07/2015 18:33, Tim Streater wrote:
In article , Jim GM4DHJ ...
wrote:

"Charles Hope" wrote in message
...
In article , Jim GM4DHJ ...
wrote:

hope you have a diesel car then ....

I do and have done so for about 25 years

horrible things ...

In what way?

Narrow power band, turbo lag, and carcinogenic smoke.

Andy

On 7/23/2015 5:40 PM, Clive George wrote:
On 23/07/2015 13:19, Big Les Wade wrote:
Alan Braggins posted
In article , Jim GM4DHJ ... wrote:
"Charles Hope" wrote in message
...
Jim GM4DHJ ... wrote:

dual mass flywheels, turbos to get any performance,
particulate filters etc etc....

What's wrong with a turbo?

ask a nissan xtrail with intercooler ....

I have a diesel Nissan X-Trail which has done over 200,000 miles.
What's wrong with a turbo?


He's referring to the fairly common fault on the T31 model where the
intercooler leaks oil into the turbo, and buggers it up by
overboosting it.

That's a bit dumb. Intercooler should be a really simple device -
air/air radiator.

Sounds more like a charge cooler.


--
Cheers,

John.

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| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
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On 24/07/2015 02:17, John Rumm wrote:
On 7/23/2015 5:40 PM, Clive George wrote:
On 23/07/2015 13:19, Big Les Wade wrote:
Alan Braggins posted
In article , Jim GM4DHJ ... wrote:
"Charles Hope" wrote in message
...
Jim GM4DHJ ... wrote:

dual mass flywheels, turbos to get any performance,
particulate filters etc etc....

What's wrong with a turbo?

ask a nissan xtrail with intercooler ....

I have a diesel Nissan X-Trail which has done over 200,000 miles.
What's wrong with a turbo?


He's referring to the fairly common fault on the T31 model where the
intercooler leaks oil into the turbo, and buggers it up by
overboosting it.

That's a bit dumb. Intercooler should be a really simple device -
air/air radiator.

Sounds more like a charge cooler.

Same thing innit? Wikipedia thinks so.

Ah, the problem with the X-trail is the intercooler leaking at the sides.

The leak (air) makes the turbo overboost to compensate which eventually
kills it.

Any oil which is in there from turbo bearings leaking a bit also leaks
out rather than getting burned.

(ie it's not intercooler leaks oil into the turbo, which would be a bit
surprising since the intercooler is after the turbo, not before it)