CitroJim's AX, C3 Picasso, Cycling and Running Tales

[demag]

Just wanted to check you were alert Jim! The Synergie came along at the right time but it wasn't as useful as I thought it would be, namely because it was a 7 seater so to move anything big I had to remove 2/3 seats and they weighed a ton! If it had been 5 seats it would have been better. But the C5 has oodles of room and drives lovely. I thought the Kia was going to be "the one", then the Synergie and hopefully the C5 definitely will be. I can't keep spending money on cars at my age.

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[CitroJim]

Did a little bit of work on an XM this afternoon. Undoing a common 'modification' carried out by a certain dealer who forces the suspension into permanent soft mode by wiring both electrovalves to a switched 12v supply.

Permanent soft mode on an XM is both a bit dangerous in my opinion and makes the car ride a bit like a boat.

I put it all back to normal, carried out the diode mod whilst doing it, rand diagnostics, cleared the faults in the Hydractive ECU and all was found to be working beautifully...

I did find the rechargable batteries in my portable oscilloscope no longer seem to be...

Goodness knows why the dealer in question does this 'mod'. I've seen (and reversed) a good few now and apart from often needing the diode mod I've never found any significant faults with the ECU, electrovalves or the sensors...

Rather enjoyed myself if truth be told... It's been a while. I believe the owner of the XM is happy too...

[demag]

The suspension on my XM was solid when I bought it. It had been maintained by two Citroen mechanics. Yeah? I don't think so. It took a long long time to soften the suspension, including the diode mod, running on hydrauringe flush and replacing spheres. It ended up with BX comfort spheres on the front and eventually the ride became quite acceptable. There was a huge suspension thread on the XM Forum that went on and on and on.

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[Mandrake]

Did a little bit of work on an XM this afternoon. Undoing a common 'modification' carried out by a certain dealer who forces the suspension into permanent soft mode by wiring both electrovalves to a switched 12v supply.

Permanent 12v ?

Surely that would overheat the coil ? The coil is about 3 ohms so at 12v that would be 48 watts and at 14v 65 watts.... that's why it is pulse width modulated in the first place, to bring the power dissipation down...

Permanent soft mode on an XM is both a bit dangerous in my opinion and makes the car ride a bit like a boat.

Indeed. Without the automatic switching to hard mode the suspension easily bottoms on things like hump back bridges. Not safe...

[CitroJim]

Permanent 12v ?

Surely that would overheat the coil ? The coil is about 3 ohms so at 12v that would be 48 watts and at 14v 65 watts.... that's why it is pulse width modulated in the first place, to bring the power dissipation down...

You'd have thought so Simon but no, they seem to survive for ages like it. As I say, I've 'de-modified' a good few like this now and all the electrovalves have happily survived the abuse...

[Peter.N.]

You could make a 'switch and hold' circuit where you use 12v to open the valve and then say 6-9v to hold it open to overcome the overheating. If you don't want to go electronic you can use a relay with a capacitor across the feed voltage which in turn is fed from 12v with a suitable series resistor. This will apply 12v to open the valve and you can adjust the value of the series resistor to give the required holding voltage.

Peter

[ekjdm14]

You could, if you wanted the XM to ride like a boat but I think the purpose of Jim's work was to remove this mod

And demag's pair of Citroen mechanics sound like the ones who looked after a certain Xantia the last couple of years

[CitroJim]

You could, if you wanted the XM to ride like a boat but I think the purpose of Jim's work was to remove this mod

Yes, Exactly! It was to remove the 'mod'....

[Peter.N.]

If you want really soft fit a set of accumulator spheres.

Peter

[CitroJim]

If you want really soft fit a set of accumulator spheres.

It's fun, did it just to see what it would be like once and by golly it's boaty!

[Peter.N.]

I did one side of one of my XMs and drove along the forest track and you could feel virtually no vibration on the accumulator side, I imagine it must be a bit like a DS, they look beautifully soft but don't seem to roll much, they have all gone down hill since.

Peter

[myglaren]

Here is something that seems to be right up your street Jim:



Don't know where else to put it.

[bobins]

I can't remember for sure if it was Criggion, or Rugby radio station (pretty sure it was Rugby though), but I was lucky enough to visit there just before it was denuded of a lot of its kit. One of the things they were chucking out was a bag of wooden wedges used to 'tune' the tuner i.e. keep it in shape. Suffice to say the wedges were rescued from the skip and are now being used as door stops in a site that needed an awful lot of doorstops Hope the Science Museum don't want them back

[demag]

I used to drive past there a lot in the 90's back and forth to London.

[Peter.N.]

What frequency is 19km?

Peter