Just finished watching Watchdog. It seems there is plenty to complain about the Peugeot 206 both over 3 years old and new. A number of viewers have written in about their car stalling.
Peugeot, to give them their due are investigating the problem and some owners report having sucessfully had the faults fixed under warranty.
I felt it was worth posting this in case anyone here is experiencing problems.
Hugo
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Peugeot, to give them their due are investigating the problem...
Only because it's been on Watchdog. They sent a team of engineers to the Watchgdog office yesterday - can you imagine them doing that in other circumstances?
I've had several Peugeots over the years, but once my current 406 is gone, never again. Any car can have problems but (sweeping statement follows) the dealers are inept and Peugeot couldn't give a toss about its customers.
I wonder if this is a RHD only issue - if it happens on all 206's then there must be many 1000's with the same problem?
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I've had several Peugeots over the years, but once my current 406 is gone, never again.
At one point, I said this about another make of car. Then I realised that how good cars are depends on how good the manufacturer's employees/management are in that particular era ~ and this is obviously subject to variation both ways. Now, I don't have any long-term preconceived ideas as to how good a particular make is ~ I look at how good the current version of a particular model of car is.
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L\'escargot by name, but not by nature.
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The problem of idle speed control is really quite difficult.
To reduce fuel consumption when idling, the idling speed should be as small as possible. However, when the engine is running slowly, disturbances in load demand create a larger fluctuation in engine speed.
For example, if you hold the engine at 3000 rpm and switch in the heated rear window, the revs will drop a small amount. If you repeat this at just above idle, say 1200 rpm (so that the ECU will not apply any idle speed control action in addition to your throttle pedal control), the engine speed drop will be greater.
So, the idle speed controller has to be able to apply rapid control actions to a non-linear and time delayed system, keeping the engine speed as close as possible to the minimum speed beyond which rough running and stalling would be likely.
For those who are interested in the technical side of control systems on cars, I can recommend the book, Automotive Control Systems, by Kiencke and Nielsen, published by Springer and the SAE. The book is aimed at those who already have capability in engineering maths, but also has clear explanatory sections.
number_cruncher
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*Automotive Control Systems, by Kiencke and Nielsen* Sounds interesting. .I grew up via circuit design and then into systems design.
*So, the idle speed controller has to be able to apply rapid control actions*
In the end I think it comes down to a combination of doing lateral thinking and how much effort and money can go into solving the problems (reducing risk).
As an example, if step changes in electrical demand (back window heater) prove very difficult to handle, build a system that does not have any! .Make it so that the switch merely initiates the action of something else turning the power on more gently.
Of course, if you build a car with duff parts you need an extremely clever system --ha ha.
I am too long away from present electronics to know what is going on. Smooth control is probably already a feature?
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Hi buzbee,
Yes, smooth control and feedforward for some heavy and easily predictable engine loads, such as air-con and power steering loads is a feature.
The idle speed controllers of the fuel injected cars in the early 90s was really quite basic - little more than P + I. It was also quite easy to fool - it was obvious there was no anti - windup strategy, you could quite easily make the car sit idling at 2000 rpm or so, gradually slowing as the integral action cleared. Modern controllers tend not to get caught out so easily.
I think that the desire to get the engine running slowly for emmissions and fuel consumption reasons has, however, outpaced the capability of the control system to robustly prevent stalling under all circumstances.
In essence, I agree with what I think you are hinting at - that manufacturers of cars won't spend much money or use good quality parts unless they absolutely have to - idle speed control probably isn't too high on their priority list.
number_cruncher
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