Back home safe and sound - I stopped briefly three times so it took me about 4 hours to get home even though I had my foot down most of the way...
Overall very pleased, but there are a few more things that need doing than I was hoping for, fortunately not MOT items. The two big problems for me are spheres and wheel balance.
The spheres are very hard indeed, from the info passed on from Jim it appears that the strut spheres have all been replaced in the not too distant past and indeed look green and clean with no rust, but the centre hydractive spheres (and accumulator and anti-sink spheres) were all over-looked and look very old and rusty, and are probably punctured or at least very flat. The rear has almost no give and was very bouncy, the front not so bad.
I was amazed at how well the old car rides by comparison when I hopped back into it for a quick drive after getting home - and I thought the ride was quite stiff on that with its 2 and a bit year old spheres, so the spheres really need doing urgently. The accumulator sphere is almost dead flat too - I can hear the pressure regulator clicking every time I press the brake pedal, which is not good.
Nothing unexpected really - I had to fit a full set of spheres on the old one when I got it, and every second hand Citroen I've ever bought has always needed spheres right away...
Slightly more worrying is a severe wheel imbalance between 75 and 90mph (indicated) - it really was shaking quite badly through the whole car and at first I thought it was one of the rear wheels but now I think it's the front. It was severe enough that I pulled off the motorway to check the wheel bolts were tight (after remembering the thread where the guy lost a front wheel collecting his new car!) but they were fine.
The vibration seemed quite intermittent - worst at 85mph indicated, but over quite a wide range from about 75 to 90, sometimes really bad, sometimes almost not there. After a while I realised it was usually bad during acceleration and almost disappeared when I let off the throttle at the exact same speed.

I started to think about the possibility of a faulty drive-shaft intermediate bearing, or faulty drive-shaft joint, but then I noticed that turning the steering just slightly would cut the vibration right down or make it worse as well.
My suspicion is that I have one or more badly worn tie-rod joints, coupled with a moderate wheel imbalance. I had much the same problem with the old one when I first got it, although not quite as bad - a "wheel imbalance" vibration which came and went randomly and didn't really improve much when the wheels were balanced. That turned out to be the right hand outer tie-rod joint had about a millimetre of slack in it, at certain speeds and loads/steering etc it caused the wheel to "wobble" back and forth on the slack of the joint - the slightest wheel imbalance which you wouldn't normally notice gets magnified 10x by the loose joint.
That vibration never went away until I replaced both outer tie-rod joints and reset the tracking - once I did that the vibration was cured. So I'm hoping its the same problem here. I think I'll ask for all four wheels to be balanced with the MOT because although I think there is a slack joint there must still be some wheel imbalance for it to be so bad...It's possible they may pick up on steering joint slack for the MOT if its as a bad as I suspect it might be...
The steering is very heavy compared to the old one (unusually heavy) and also feels like there is way too much toe out as it has an excessively strong self centring action - but at the same time there is a bit of "loose" dead-band in the middle if you rock the wheel back and forth slightly - perhaps further evidence of a slack joint ? The steering feels very light and sharp on the old one so hopefully I can improve it.
I suspect fixing any slack tie-rod joints, resetting the toe out correctly and lubricating the two universal joints should see it right.
Brakes are ok but not great - they don't have the same sharp bite of the old one. The back lifts up under moderate to hard braking so the rear brakes aren't really working properly - they need to be given the standard treatment of freeing up the pads and pistons and they'll probably come up ok. Will try to do that this weekend before the MOT as I suspect the rears wont pass.
ABS is malfunctioning - no light on the dashboard but when braking and hitting a bump (on the front wheels I think) the brake pedal will sometimes chatter rapidly for a couple of seconds as though it's trying to prevent a skid, so I guess I have a faulty sensor...
Nothing too much to worry about so far, a bit of TLC should solve these problems.
The engine is extremely quiet and smooth - so quiet in fact that you really can't hear it!

It's not until you get to about 4000 rpm that you hear it at all, its that quiet. Under the bonnet the tappets are silent and so is the timing belt area.

It sounds like a brand new engine. The old engine sounds very noisy and "rawty" by comparison, especially when revved under hard acceleration. A fun "busy" engine sound, but not refined and a bit tiring after a while. I guess the bearings and/or bores must be quite worn on the old engine, the difference in mechanical engine noise between the two cars is huge.
Without any engine "note" there is really no clue to how much you're accelerating other than looking at the speedo, which is disconcerting...
Believe it or not, I don't think the engine is performing as well as it should be though - the old one has been running unusually well in this hot dry weather (as it sometimes does) and although the new one takes off a lot better from a standstill and pulls very smoothly at low rpm, the foot flat to the floor acceleration is a little disappointing, as if it wasn't reaching full throttle due to the cable adjustment or floor mat, however I checked both of those and couldn't find a problem.
Another thought I had is maybe the air filter is clogged up because as well as no mechanical noise, there is no "induction" boom when you open the throttle like there is on the old one... the only other thing that I'm aware of that can cause the engine to sound quiet like a pussy cat is if the timing is really retarded due to a faulty knock sensor... if that happens the engine becomes very smooth, very quiet, but also very placid and lacking in bite in the performance. I need to check for an intermittent knock sensor fault on the Lexia to rule that out.
Interestingly when I took it for a hard country road "blast" after getting home, pushing the revs well over 4000 the performance did start to pick up quite a bit, and it does seem quite a bit more responsive now after that blast than it did after the motorway cruise home. I also noticed that there is quite a big torque spike just above 4000 rpm where it suddenly opens up and becomes more rawty sounding and gets an extra kick of acceleration - similar to what I have sometimes seen on the old engine.
From my previous efforts I believe the cause of this torque spike is knock retard below 4000 rpm, at which point I remembered that Steve filled it with 95 fuel. It's possible that there is some knock retard being applied because of the lower octane fuel, which takes the edge off the performance below 4000 rpm, while the old car is running on 99 octane, so bit of an unfair test... so next fill up I'm going to try 99 V-Power for a fair test and I suspect that will improve things quite a bit. (Also a battery off reset in case the ECU has memorised bad fuel data)
Part of my perception of less than expected performance may simply be that the engine is dead silent - unless you're watching the gauges on the dashboard you really have no idea what the engine is doing...sometimes the speedo is climbing very quickly and there is just no noise or fuss at all. Another aspect of it is the gearbox is very reluctant to kick down - I have to push the pedal right down and then past what seems like a small "detent" before it will kick down, whereas the old one will kick down much more readily. Not sure if that's an issue with the TPS/MAP, the throttle cable, maybe even the software version of the gearbox ECU, but it needs further investigation.
The idle control valve seems to be seized - on a hot engine with accessory load off it can't bring the idle speed down and is trying to idle at nearly 900 rpm. Hopefully a clean out will fix it as they are not cheap!
The gearbox is beautifully smooth 99% of the time. The major difference is the torque converter is silky smooth

Boy what a difference in the way it takes off. I had gotten used to a torque converter that was harsh, abrupt, and noisy... not only is it silent and silky smooth but you can really feel the torque multiplication working. You don't feel that on the old car.
I've thought about this possibility before Jim - I think the one way roller clutch in the torque converter may have failed in the old gearbox. As you probably know the stator is supported on the turbine (?) using a one way roller clutch which allows it to free wheel in one direction but locks in the other direction. In the coupling phase the stator is allowed to rotate freely to minimise losses but in the stall mode when there is a large rpm differential the force of the oil tries to turn the stator against the one way clutch which locks the position of the stator and allows torque multiplication to occur.
If the roller clutch fails and allows the stator to free wheel in both directions the torque converter basically just becomes a simple fluid coupling with no torque multiplication - and would make it seem like the engine has lost a lot of the power but its actually the torque converter failing to work properly! Hard to describe exactly but if you drove both cars you'd know exactly what I mean...
Pulling up to a stop the shift down into 1st is a bit abrupt but I think that's partly because the ICV is causing the engine to idle too fast, so I think that will go away when the ICV issue is fixed.
Cruise doesn't work as already mentioned, I'll look at that as soon as I get the wiring diagrams.

The lights for the buttons on the dashboard are very dim that you can't see them in daylight - a common S1 problem from what I remember. Steve seemed to think the air con light didn't work at all but it does work - just very faint, I could see it at night. The air con itself is very strong however, even on a stinking hot 28 degree day the air con was so good on the way home that I had to keep turning it off! (Not sure if the cabin temp sensor fan is working or not, I had to turn it up to about 24 degrees before the air con stopped freezing my ***** off

)
The radiator fans have a propensity to switch into high speed easily - I'm not sure if that's a problem or just the air con running on a 28 degree day, but every time I stopped anywhere when I started up again the fans came straight onto high and stayed there for quite a while. Indicated temp stayed between 80 and 90 though. Perhaps the air con is actually over pressurised and tripping the high pressure switch ? (That would bring the fans on high)
The inside of the car is very quiet and feels "tight" and new, and the leather is like new. Electric seats, windows all work, the radio works great, everything electrical except the cruise and some interior bulbs seems to be working. I haven't had a chance to look under the bonnet or underneath since I got home although I had a quick look at Steve's.
A couple of S1 annoyances - the immobiliser is in a really stupid place - you can't see the buttons past the gear lever in park to enter your code without leaning right over, and when you're in drive you can't see the sport mode LED past the lever!!

Without a dashboard repeater like the S2 you thus can't see at a glance whether you're in sport mode or not. You actually have to lean over to the left and look down taking your eyes off the road which I found very distracting.
Same with the suspension sport/normal switch - on the S2 its a push in push out switch so you can tell just by touching it whether you're in sport mode or not, (and its not too far from your normal sight line) but on the S1 you can't tell if you're in sport mode or not by feel, so you're taking your eyes well off the road to look down at the feeble light to see which state its in... Not good.
At least one of the plips is working - I programmed it while I was still at Steve's, I think the other one is working too, but to program both I need to take one out of its casing as I don't have a third key to put in the ignition. Going from a S2 RF remote back to a short range infrared remote feels a bit archaic, but I knew what to expect having owned a S1 before.
It probably sounds like I don't like this car but I really do! It just has quite a bit of sorting out to do, in particular spheres, wheel balance, steering, brakes, and find out why the engine is a bit flat. I'm sure once I'm finished it will be a real cracker though.
