ECUs, fly-by-wire, multiplex wiring - who would choose it?

This is the place for posts that don't fit into any other category.

Moderator: RichardW

Do you prefer your car without or without electronics?

Poll ended at 05 Nov 2012, 01:15

I would choose my car not to rely on electronic control to make it run - this allows for an ABS control unit and airbags.
10
63%
I appreciate the benefits and complexities and prefer a car with multiple electronic devices without which it will not run.
5
31%
I drive whatever is cheapest.
1
6%
 
Total votes: 16

Northern_Mike

Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by Northern_Mike »

Peter.N. wrote:
Rattiva_Mike wrote:
Peter.N. wrote:If the electronics were 100% reliable or faults could be diagnosed easily by the average mechanic

Peter
True, but its a fact of life, back street mechanics may be able to sort out the problems but the average dealer doesn't seem to be able to, just look at the problems experienced by many motorists in Honest John's forum. Most garages seem to work on a 'try it and see' basis, if it doesn't work the customer still pays, in some cases thousands of pounds and sometimes the car still gets written off.

Peter
You are right Peter, but again, this is the fault of the owner for taking it somewhere that can't deal with the car. People are quite stupid and set in their ways when it comes to things like that. My granddad would take his Reliant Robin to a terrible dealer, where he bought it for all it's servicing and repairs. He wouldn't listen to anyone else. They ripped him off many times. My Aunt won't take her PC for repair to anywhere other than PC World. She gets ripped off regularly. She won't let me touch it. Because she's been told by someone else and seen their adverts, she prefers to pay them £80 or whatever to do a "PC Health Check" than let me have it for an hour.

It is not hard, these days, to get the information from the internet. Most people do have access. A google of "Citroen Specialist Berkshire" brings up 3 immediately that I know have Lexias and could diagnose faults quickly.

User avatar
Spaces
Posts: 186
Joined: 16 Mar 2011, 11:42

Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by Spaces »

Rattiva_Mike wrote:
Spaces wrote:Rattiva_Mike, this isn't a debate as to whether older cars are inherently more or less reliable than more modern ones
Well, yes, it is really isn't it?

They are.

I'd have a car full of electronics over an old, unsafe, hard to get parts for clunker one over an old clunker any day.

If you want one as a hobby car, fine. I do - Some may call my Xantia V6 an old clunker. It has plenty of electronics though.

As a daily driver I had to rely on? Not a chance. Modern(ish) for me any day.
Mike, 'well yes it is really isn't it?' has a very obvious answer - NO! Read the thread title, if you fail to accept what I'm asking! As I've mentioned you can buy a Xantia with or without electronics which run the engine and without which it won't run. I'm asking people whether or not they choose the electronics, not whether cars post 90s instead of pre 90s are inherently more reliant. Can't make it any clearer.

Northern_Mike

Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by Northern_Mike »

Why is your entire post about how reliable your old cars are then?

User avatar
Spaces
Posts: 186
Joined: 16 Mar 2011, 11:42

Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by Spaces »

Rattiva_Mike wrote:I replaced the points and coil on two my 2cvs with 123 Electronic ignition units. It gave them slightly more response and made them far more reliable, removing the points and the heat-susceptible original coil and leads out of the HT equation. That's a very basic example I know, but it shows that electronics can, and usually are a better option.
So you replaced the ignition coil and HT leads at the same time, yet are sure the 123 ignition made all the difference. Hmmm. You sure the coil and old leads weren't the problem?

If you have problems with a car's ignition, then replacing the points with a box of tricks will only delay the problem - replacing points and condensors with electronics to 'repair' a fault is not good practice. There's nothing whatsoever wrong with a 2cv's points and condensor, if they are up to quality (avoid the English make). Just that they require maintenance every 6 to 12,000 miles - about 20 minutes' worth. From what I've heard (from suppliers), 123 have many returns - and if it fails you are utterly, utterly stranded unless you carry the old points and their box, the advance weights, cam and ring spring clip plus all the tools needed to refit these. Or a spare 123.

My choice is a points-assisted electronic box - that way, you retain the fundamental reliability and repairability of the mechanical points but have transistors switch the lt circuit, boost the spark and remove the need for a capacitor. If it fails, you can remove it and use the points as intended. These boxes are by common sense mounted away from the direct heat of the engine, and above water levels.

User avatar
Spaces
Posts: 186
Joined: 16 Mar 2011, 11:42

Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by Spaces »

Rattiva_Mike wrote:Why is your entire post about how reliable your old cars are then?
To remind people there is still a choice - not everybody has to be at the mercy of those with intimate knowledge of what goes wrong with the electronics on a particular model of car. You speak with such authority regarding the inherent superiority of a car run by computers - and you have a good point, I'm quite aware of the advantages as well as the problems - but whilst there is still a choice for Citroen buyers - particularly Xantia folk, which is what this forum seems to centre around - then is it not fair and right that the benefits of each technology are honestly aired?

There is a tendency in the media, even on here to disregard anything which is 'yesterday's tech' as old hat and inferior. I'm just asking people on here what their views are, not asking for a debate on whether or not an older car is better than a newer one. After all, BMWs were electronically quite complex by the end of the 80s, but you could still buy an ECU-less Golf wel beyond the mid-90s. The idi Xantias were fairly straightforwards, too - some people have a set of priorities which doesn't include trying to work out their car's electronics/paying garages even more to give them a reliable, working car.

User avatar
CitroJim
A very naughty boy
Posts: 42571
Joined: 30 Apr 2005, 23:33
x 1338

Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by CitroJim »

And then there's people who thoroughly enjoy getting to grips with all this electronic stuff. I do immensely. It's an interesting challenge and keeps the brain alert.

For instance, I now have a car that runs on LPG - electronically controlled - and prior to that I knew nothing about how LPG worked. I've spent many enjoyable hours learning about it and getting to understand it and what all the obscure black boxes under the bonnet do.

That's the fun for me and whilst I'm not saying it's everybody's cup of tea, it's why I have three cars that positively bristle with the stuff.

And in all that time the only true breakdown I've suffered necessitating recovery was when an ignition coil failed on a V6 - that could have happened on any car - even one with points...

User avatar
DickieG
Monaco's youngest playboy
Posts: 4896
Joined: 25 Nov 2006, 10:15
x 14

Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by DickieG »

Spaces wrote:My choice is a points-assisted electronic box - that way, you retain the fundamental reliability and repairability of the mechanical points but have transistors switch the lt circuit, boost the spark and remove the need for a capacitor.
Not a good idea I'm afraid as points systems (electronic or otherwise) are completely knackered before even 50k miles due to wear in the distributor, yes they will work to a degree to get you home but forget accuracy with timing on each cylinder, it will be random in the extreme. Take a look at a raster pattern on a Crypton tuning oscilloscope and you'll notice the firing lines are all over the place, superimpose those firing lines over each other and you'll observe that on say a four cylinder engine the pattern will be four individual lines scattered across the screen rather than the four firing lines working/looking as one.

In layman's terms using a timing strobe say you set the ignition timing to 6° BTDC on cylinder no 1, on the other three cylinders they will fire way beyond either side of 6° so some fire at 10° BTDC, others at say a 5° ATDC. You can test this by timing the engine in the normal way then swap the HT lead connection to the cylinder which fires when no 1 is on its exhaust stroke, if the timing mark has moved the distributor is knackered.

One of the first things I did to my DS when I bought it was to ditch the distributor and replace it with a 123 system, something I cannot stand is an engine that does not run smoothly.

123 ignition demonstrate this issue on their you tube video shown below


Northern_Mike

Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by Northern_Mike »

Spaces wrote:
Rattiva_Mike wrote:Why is your entire post about how reliable your old cars are then?
To remind people there is still a choice - not everybody has to be at the mercy of those with intimate knowledge of what goes wrong with the electronics on a particular model of car. You speak with such authority regarding the inherent superiority of a car run by computers - and you have a good point, I'm quite aware of the advantages as well as the problems - but whilst there is still a choice for Citroen buyers - particularly Xantia folk, which is what this forum seems to centre around - then is it not fair and right that the benefits of each technology are honestly aired?

There is a tendency in the media, even on here to disregard anything which is 'yesterday's tech' as old hat and inferior. I'm just asking people on here what their views are, not asking for a debate on whether or not an older car is better than a newer one. After all, BMWs were electronically quite complex by the end of the 80s, but you could still buy an ECU-less Golf wel beyond the mid-90s. The idi Xantias were fairly straightforwards, too - some people have a set of priorities which doesn't include trying to work out their car's electronics/paying garages even more to give them a reliable, working car.
The issue here is that there isn't that much of a choice at all any more. All the vehicles which you mention above - The IDI Xantias, ECU-less Golf, the Merc W123 and 124 series are all at least 15 years old. The Mercs, obviously are rather older than that. Therefore, unless people are prepared to do their own maintenance then they are still at the mercy of a mechanic, whether he has a code reader or not. There aren't that many people who do their own maintenance now, unless they are an enthusiasts like some of the people on this forum.

I can still change a set of points or set up a carburettor properly. It's just something I'd rather not have to do ever again. One of my favourite magazines is Practical Classics. I'd love to own some of the cars they test in the group tests - but as a hobby as they're all unfeasible to me as daily drivers, electronics or no electronics.

Time change, technology advances. When those advances happen, problems occur before the technology is perfected. It happens in all areas. Cars, aircraft, computers, televisions. Car electronics are now well enough developed that I have trust in them.

People have been trusting high levels of electronics on airliners for over 30 years since the 767 first flew. If electronics are reliable enough for that, then they're good enough to be in my car.

Northern_Mike

Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by Northern_Mike »

Spaces wrote:
Rattiva_Mike wrote:I replaced the points and coil on two my 2cvs with 123 Electronic ignition units. It gave them slightly more response and made them far more reliable, removing the points and the heat-susceptible original coil and leads out of the HT equation. That's a very basic example I know, but it shows that electronics can, and usually are a better option.

/quote]
So you replaced the ignition coil and HT leads at the same time, yet are sure the 123 ignition made all the difference. Hmmm. You sure the coil and old leads weren't the problem?

If you have problems with a car's ignition, then replacing the points with a box of tricks will only delay the problem - replacing points and condensors with electronics to 'repair' a fault is not good practice. There's nothing whatsoever wrong with a 2cv's points and condensor
Yes, I'm sure it was the problem. I did check them first. If you use a 2cv as a daily driver, and drive it hard, the points need checking regularly. What happens is that they keep going out of adjustment because the little cam wears out and they start to go off-tune again. I got bored of this with the first one, stuck a 123 on it. The second one got a 123 as part of the first service I did on it.

User avatar
spider
Posts: 3949
Joined: 05 Jan 2010, 15:28
x 64

Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by spider »

There's nothing wrong with electronic ignition or (sensible) fuel injection. I've done many points (used to own some Beetles a few years ago amonst other ancient Fords with points) and they are a bit of a pain, true you can do a roadside bodge if needed compared to module failure for instance, but I'm happy with electronic ignition.

I think the 'concern' here is the electronics are getting so complicated now they are falling over themselves rather than being a benefit. My point about a Com2K vs a standard switch / relay springs to mind again.

User avatar
Xaccers
Posts: 7653
Joined: 08 Feb 2007, 00:46
x 3

Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by Xaccers »

Rattiva_Mike wrote: People have been trusting high levels of electronics on airliners for over 30 years since the 767 first flew. If electronics are reliable enough for that, then they're good enough to be in my car.
Don't they have multiple redundant systems because/i] they can go wrong? A car doesn't get that luxury.
I always remember hearing about the vectra with the speedo being affected by the radio so it wasn't legally drivable.

User avatar
CitroJim
A very naughty boy
Posts: 42571
Joined: 30 Apr 2005, 23:33
x 1338

Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by CitroJim »

Xac wrote:
Rattiva_Mike wrote: People have been trusting high levels of electronics on airliners for over 30 years since the 767 first flew. If electronics are reliable enough for that, then they're good enough to be in my car.
Don't they have multiple redundant systems because they can go wrong? A car doesn't get that luxury.
Yes, but if your 767 conks out half-way to Ulaan Bataar you can't just pull over onto a passing cloud and wait for the aeronautical AA to come and recover you home...
spider wrote:My point about a Com2K vs a standard switch / relay springs to mind again.
Complex electronics are cheaper than simple mechanisms Andy and that's why you now see electronics in the most unlikely of places. Win-win for the maker. They're cheap and with them he can offer all kinds of mad functionality that a mere switch never could and thus impress the great unwashed and Jeremy Clarkson with their brilliance; they don't see it for what it is - a cost-cutting exercise...

Think of the difference in cost between say, a mechanical Bosch diesel pump and a complete HDi setup. Half certainly and maybe much more in favour of the HDi.

User avatar
Xaccers
Posts: 7653
Joined: 08 Feb 2007, 00:46
x 3

Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by Xaccers »

CitroJim wrote:
Xac wrote:
Rattiva_Mike wrote: People have been trusting high levels of electronics on airliners for over 30 years since the 767 first flew. If electronics are reliable enough for that, then they're good enough to be in my car.
Don't they have multiple redundant systems because they can go wrong? A car doesn't get that luxury.
Yes, but if your 767 conks out half-way to Ulaan Bataar you can't just pull over onto a passing cloud and wait for the aeronautical AA to come and recover you home...
Just follow Air Transat Flight 236 and glide to the Azores :)

Northern_Mike

Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by Northern_Mike »

Xac wrote:[quote="CitroJim]
People have been trusting high levels of electronics on airliners for over 30 years since the 767 first flew. If electronics are reliable enough for that, then they're good enough to be in my car.
Don't they have multiple redundant systems because they can go wrong? A car doesn't get that luxury.[/quote]

Yes, but if your 767 conks out half-way to Ulaan Bataar you can't just pull over onto a passing cloud and wait for the aeronautical AA to come and recover you home...
[/quote]

Just follow Air Transat Flight 236 and glide to the Azores :)[/quote][/quote][/quote]

Bah, Air Canada 143 (aka as the Gimli Glider), also a 767, did the gliding thing 18 years before Air Transat. Just goes to show one thing - all the redundancy in the world doesn't help if your ground crew can't add up. A tremendous piece of flying, as was Transat.

<Jim, do not watch the link below>

" onclick="window.open(this.href);return false;

Northern_Mike

Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by Northern_Mike »

Xac wrote:
Rattiva_Mike wrote: People have been trusting high levels of electronics on airliners for over 30 years since the 767 first flew. If electronics are reliable enough for that, then they're good enough to be in my car.
Don't they have multiple redundant systems because/i] they can go wrong? A car doesn't get that luxury.
I always remember hearing about the vectra with the speedo being affected by the radio so it wasn't legally drivable.


A car has redundancy on the brakes and steering. If your PAS fails, there is a mechanical link to the wheels, which you can wrestle to the side of the road. The brakes have multiple circuits and a parking brake. So, I'd say that like an aircraft, cars do have redundancy on the essential controls.