Zel's Fleet Blog - BX, Jag XJ-S, Sinclair C5, Mercedes 208D & 230TE, AC Model 70.

[mickthemaverick]

Sounds like a good project Zel. Look forward to further installments!

[Zelandeth]

Sounds like a good project Zel. Look forward to further installments!

Should be interesting. It's actually quite a nicely designed little unit mechanically - which I guess is why it's still here after 33 years. It's just the fancy electronics which have let it down. I need to find a spare hour to sit down, draw myself a schematic and make a shopping list for the parts I need.


While the Trabant generally runs fine, she's always been a bit grumpy when dropping to idle after working hard for any period of time. The idle has always been a little low anyway, but with the slightly warmer weather arriving this has brought it down to a 50/50 chance of stalling for a minute or so after stopping after a higher speed run unless I keep a tiny touch of throttle on. We're not talking much, just the weight of my foot on the pedal is enough, and if it does stall it will instantly start back up just fine, so we're not looking at a soft-seize situation or anything, I think the idle is just a tiny bit too low.

Aside from clearing a bit of sediment from the float bowl, I've barely even looked at the fuel system as a whole on this car, so this was a good opportunity to look at things a bit closer.

Compared to what you're probably used to, this carb has very little in the way of adjustments available. There's an idle mixture screw, a main mixture screw, a fast idle preset that's part of the choke linkage...and that's it. Not even an idle speed control. That's handled entirely by setting the pre-load on the throttle cable itself. Which does make a certain amount of sense as it ensures that even when the throttle is notionally closed that some fuel (and therefore oil) will still be delivered to the engine even in the absence of anything fancy like oil injection. Keep it simple, stupid.

The only other screw on the carb is part of the choke linkage and is involved in bringing the idle speed up while the choke is on...this is what many, many people mistake for the idle speed adjustment screw.



The idle mixture screw is really easy to get to. It's the large slotted screw roughly centre frame below.



I shouldn't have been able to wiggle that by hand. It had all but unscrewed itself. Took several full turns in before it did anything whatsoever, and even then there's very little drag on it which suggests to me that the O-ring under there has probably seen better days and is likely causing an air leak.

Speaking of air leaks, that's something it's worth keeping an eye out for those on a two stroke. A really quick and dirty way to check for them is to cover the intake with your hand with the engine at idle. It should cut out pretty much immediately. Not two or three seconds later. Like mine does. Hmm. Likely candidates are the carb to block join (especially as the bolts are a bit of a pig to get to as the exhaust, alternator and carb itself are right in the way), jug gaskets or crank seals. Everything there aside from crank seals I have in stock already. Though between the obvious issues we have with the carb adjustment screw seals and the fact that it's weeping from the float bowl cover a tiny bit I think we'll be ordering an overhaul kit for it.



While I was under the bonnet I took care of the fan belt that seemed a little loose. Fun fact: If you're unbolting things right next to the alternator it's smart to disconnect the battery first. Otherwise it can be really exciting if you drop a 17mm spanner and it brushes against the main positive connection - thankfully as it fell to the ground rather than welding itself in place. That will teach me to be lazy. Won't make that mistake again for a couple of years!

The bite point of the clutch has always been really quite high. Though there was loads of adjustment available on the cable so I gave that a bit of attention. There was basically no free play on it before, but with a good 1/4" of tension taken out of the cable things seem a lot more sensible.



Interestingly this also seems to have significantly reduced the clutch judder. It's still there, but way less pronounced than it was. Which makes no sense to me as the free play in the cable shouldn't in any way impact on how the clutch itself engages as you release the pedal. I'm not going to complain about free fixes, but ones I don't understand always result in a certain amount of head scratching. My only real theory here is that with the clutch not fully releasing before that the release bearing (which is just a graphite bushing in this case) was getting hot and that was causing things to bind up. No idea, but that's the best theory I've got.

Last matter I attended to was the very worn out rubber bushes on the thumbscrews which secure the front panel. They very much looked 40 years old.



For the second time in a week my salvation came from the random plumbing supplies box in the form of a tap washer.



Much better.



Which brings us up to date. Time to get a carb overhaul kit ordered in along with a set of crank seals. Whether I need them at this stage or not it makes sense to get them on the shelf as they'll be needed one day I'm sure.

The bite point is now about 1/2 way through the travel and feels much more natural.

[CitroJim]

Good work Zel

[Zelandeth]

Time to get stuck in to the AC control system project. Basically just to put together a rough schematic so I could start to make a shopping list.

As we all know, the first generation of a schematic always ends up looking at a complete disaster as you inevitably forget a bunch of things. It's a starting point though.



Which I then tidied up (a bit) in Kicad.



Sorry, I can't export it as an image with anything aside from a black background as far as I can tell. I'll take a couple of screen shots tomorrow and paste them together as it will be about ten times easier to read than that mess above.

It's only intended as a rough guide/sanity check anyway. Especially as this package is more set up for microelectronics and such and it doesn't have any provision in the parts libraries for things like multi speed motors, relays with auxiliary contacts, a proper potential relay or a way to really represent a standalone unit like the temperature controller properly. I've already decided on three or four things I've forgotten or want to do differently since I put that diagram together. I completely forgot the condenser fan motor for one thing!

What will be interesting when I actually look at it properly will be seeing if I actually remembered how to wire up the aforementioned potential relay properly. It's been probably 15 years since I last messed with this stuff.

It also looks a bunch more complicated than it really is because I'm me and I have an opportunity to make a control panel that I can cover in switches and status indicator lights, so there are no less than nine neons and an LED (which will probably turn into a neon). Oh...having forgotten the condenser fan means I'd missed another excuse for a status indicator.

For the sake of simplicity nearly all the relays will be the same type (I want one with an auxiliary contact for the cooling enable relay so I can have it physically lock out the heating circuit if it's cooling in case something went awry with the controller). I'll probably just use an integrated motor starter assembly as it's barely any more expensive than me buying the relay and cap separately, and it's a nice tidy solution. All of the caps in there will be getting replaced - I think the run capacitor on the blower was replaced at some point, but the rest are all 33 years old I believe and are likely past their best.

Watch this space for a version 1.1 tomorrow. Then I'll have an excuse to go digging through the industrial control and indicator section on either RS or Farnell's websites...which is probably dangerous as I'm sure I'll end up ordering a bunch of things completely unrelated and that I don't need.

Bunch of relays, small mountain of neon indicators, some capacitors, handful of passives, some DIN rail (and appropriate sockets for the relays), fuse holder, some switches, and suitable wire to string it all together, then we should be good to go I reckon. Probably the biggest challenge will be making a tidy job of the front panel!

[Zelandeth]

This afternoon there were a bunch of actually useful things that I really should have been doing. Instead I was messing about with this nonsense.



Should be slightly easier to read than the previous version (should be able to see a full size version by clicking on it). I've also corrected a couple of really stupid mistakes I'd made.

Edit: Already spotted one missing connection...

[Zelandeth]

Fouled up the blower wiring on that diagram, I'd somehow hooked it up to the 24V line...has now been fixed, but I've not taken an updated version of the complete diagram yet.

Most of the neons are actually going to end up being LEDs, as I can't find any of my usually preferred style. So we've gone with a very 80s style looking square indicator instead. On the plus side, they have detachable lenses so I can print legends to go in them which will look far tidier. Plus I've been able to find identically styled latching push buttons for the three on/off switches I need. So should be able to make a reasonably tidy job of the front panel. Assuming I can drill a dozen or so holes nicely lined up!

In other news, it turned out that I had managed to set the idle speed on the Trabant far too high. I've tweaked that a bit lower today. Still slightly on the high side I think, but I'd rather it was too high than too low. Not really doing any harm at least.

[Zelandeth]

My mission to build a new control system for my AC unit has taken a large step forward today with a box of bits arriving from RS.



Obviously not the Unimax switch by the keyboard, though that's going to feature later. This was a little over £100 worth of relays, sockets, a breaker and some DIN rail. Now I could probably have got relays for about £1 each on eBay or Amazon. However where power electronics are involved I'd really rather be buying things from a reputable source thanks.



The sockets here were £5 apiece.

So this will be the bulk of the control hardware.



The breaker oddly was cheaper than a fuse holder.

The DIN rail will obviously need to be trimmed down. However I could buy 0.5M for £10, or 1M for £3.75...and I figure it'll be useful for another project in the future I'm sure.

The actual brains of the operation will be this little box of tricks.



This is specifically designed for refrigeration applications, so it already has things like an adjustable hysteris control, anti-cycle timer built in. That saves me a lot of hassle. It just takes mains in, has a pair of terminals for a standard K type thermocouple, and provides a pair of relay contacts for heating and cooling respectively.



I've found them to be astonishingly dependable despite costing something daft like £10 provided you're not using the internal relays to switch heavy loads - and I'm just using it here to drive one of the power relays you've seen above.

I'm still waiting for a couple of items. First being a new potential relay to handle starting the compressor, some wire to connect the whole lot together, a whole bundle of panel indicators along with a couple of buttons.

One of those buttons and two lamps have been rendered redundant since I started this project. Basically because I remembered that I've had this thing rolling around forever.



Probably one of the most over-engineered pieces of equipment I've ever owned.



In addition to four sets of contacts, it also has four lamps allowing the two parts of the face to be illuminated independently.



With a suitable legend made up (conveniently I do have transparency sheets for my printer) this will allow me to combine the "on standby" and "power on" indicators in here. In an appropriate typeface of course.



Yes, I did spend waaaaay too long tracking down that typeface.

If this switchgear looks familiar to you, that's because these switches were used (in addition to a plethora of military applications) in the iconic NASA Mission Operation & Control Room in Houson from the Apollo all the way through the Shuttle era. They used virtually identical ones from two makers, but the only real difference is a barely detectable difference in the bezel that you'd never see if you weren't specifically looking for it. Obviously since it's become widely known on the internet as to what types were used their prices have gone through the roof, whereas these used to be readily available from surplus specialists for $10-20 apiece. I grabbed this one just before they started to go silly. Not at all unusual to see them with $100+ price tags these days. However I've always wanted to actually have this one DO something useful, being an isolator for the 24V control circuit here seems a good fit. Absurdity in terms of the degree of over-engineering, but that's half the fun of it. I mean, that's kind of true of the whole concept I'm working with here. I'm doing this because I'm enjoying it rather than because I necessarily need to.

Bit of graphic design to be done while I wait for the last few parts to arrive, as I'll need to design a new front panel to accommodate the controller, buttons, a rotary switch for the fan speeds and a load of status indicators in a tidy and logical way.

-- -- --

The Partner actually saw a bit of attention yesterday. One of the primary annoyances I'd had since the car was bought were a plethora of rattles and squeaks from the tailgate. I knew one of the main culprits here was the trim as you could see it bounce every time you closed it. Two random self tappers into the frame suggested that someone had previously had a go at dealing with this. Removing them and pulling the panel revealed several broken clips.



That won't have been helping our case. Thankfully I did have suitable replacements in stock so swapped those out. This helped, but the panel was still able to flop around a lot in the middle...I think just by virtue of it being the boot trim in what is essentially a van. So I followed the example of the previous owner and added a couple of machine screws where the worst flex was (albeit properly drilling and tapping the holes), which has helped massively.

I found another huge amount of rattling was being caused by these grilles in the frame.



I did faff about for about half an hour using several methods to try to shut these up, but eventually just opted to delete them for now. I just couldn't get them to not rattle.



Next step will probably be to seal them in place with some flexible sealant. That's a job for another day though.

Again, a great improvement. Still rattling though. Plus squeaking.

The squeak was very clearly coming from where the tailgate was touching the guards on the tail lights.



This was something I'd been meaning to look into for a while, as the whole clusters were clearly not sitting properly.



The reason for this turned out to be a previous owner failing an IQ test. When they couldn't get the clusters out, rather than consulting the handbook to look for the clips they had missed, they just reverted to brute force and snapped both clips on both clusters.



Given that the first three matches I found on eBay for second hand clusters clearly also have snapped clips this is apparently a common issue. I'll clearly need two replacement clusters though to get them properly installed not fouling on the tailgate. Removing the guards has got us clearance for now at least. I want to give them some fresh paint on them anyway as they're pretty scruffy.



They're far heavier than I'd expected. I really thought they would just be really flimsy things but they're a good deal more weighty than I'd expected.

Last obvious rattle source is actually the trim on the outside of the bootlid. As evidenced by the witness marks from where it's been moving.



Sure enough, of the four mounting points I can see three are broken. I'll add that to the shopping list then.

I've also adjusted the stop buffers - and improvised a replacement for the missing one which has further helped. That has vastly improved how positively it closes if nothing else. Not expecting silence in the cabin, but I'd like to get rid of as many unnecessary squeaks and rattles as I can.

[CitroJim]

Excellent stuff Zel

[MattBLancs]

Love these types of fix, rattles really get in my nerves!

Those white brittle trim clips are horrible things. Literally single use, all but one shattered when removing my C5 boot trim.

This is my go to universal rattle damping solution:
https://www.googleadservices.com/pagead ... QDA&adurl=

Oh, link gone mad! Screwfix stormgard self adhesive foam draught strip stuff

[Zelandeth]

To be honest the tailgate is the one thing I'd really like to change on this car in terms of design. It's huge, heavy and unwieldy, and it doesn't really surprise me that a bunch of clips have broken. The split van-style vertical doors on the Caddy were miles better. Required half the amount of space behind me to open (it's only a matter of time I reckon until I smack myself in the teeth opening it), and was far easier for loading the dogs. I've come back to load shopping on several occasions where I've had to pull forward in the space to give me enough room behind to open the tailgate and load my shopping. Yes, the car style tailgate does make it more "car like" in the eyes of the buying public (and it's obviously cheaper) I'm sure - but I'd far, far rather have seen the rear doors of the cargo van version there. Guessing that was never an option though. I'm certainly not aware of ever having seen an MPV variant Parlingo with a split vertical rear door.

[MattBLancs]

Is the body molding different between Berlingo Van and Berlingo Car versions? Or could a pair of van doors be fitted to yours?

My dad has next generation Berlingo and agree the huge door is a pain!

[Zelandeth]

Is the body molding different between Berlingo Van and Berlingo Car versions? Or could a pair of van doors be fitted to yours?

My dad has next generation Berlingo and agree the huge door is a pain!

I don't *think* the actual pressings are different. Wouldn't surprise me though if there were things like strengthening plates for where the hinges would mount which simply weren't fitted to the car variant.

If it was a simple swap I'm sure more people would do it! I'd definitely consider it myself as it would be a big quality of life improvement I reckon.

[CitroJim]

That big tailgate terrifies me and to be honest the C3 Picasso one is not a lot less terrifying!

I've had a couple of accidents involving my head and tailgates with failing struts, latterly on my erstwhile Saxo. That one caused a very nasty and bloody gash...

These days I'm very careful..

One significant advantage of a big tailgate is that it acts as a handy 'roof' in wet weather when using the car as a mobile office...

[Zelandeth]

The fixes on the tailgate have definitely vastly improved the number of cabin rattles in the Partner. I've been running round like a headless chicken last couple of days trying to get everything I need to before I head away for the weekend tomorrow, so have done quite a few miles in it last couple of days.

Once I'm back I think I really do need to get shopping for a new axle, it really is pretty miserable on anything other than a perfect surface now, with the rear end being really crashy - which is just exacerbating any rattles. Knocking 5psi off the tyre pressures has helped a bit, but that's a sticking plaster rather than a solution.

Having largely shut up the tailgate has highlighted the next most obvious source of knocks and rattles, and that's the nearside rear door. My money is on wear on the locating pin or the bush it slots into when the door closed. If it's anything more involved than that it will likely be ignored for a while as I'm not getting deeply involved in taking apart sliding doors. Plus their tendency to rattle is probably the biggest drawback they have aside from weight, so I'd likely be on a hiding to nothing anyway.

Had hoped to get time to clean the Trabant today. However just ran out of time. So it'll just have to make the trip absolutely covered in pollen.



Doesn't look like it will be raining where we are over the weekend so have chucked the carpet and trim back in the boot.



Not sure why that to my mind makes the car feel so much less shoddy, but it does. Here's the before photo from the carpets there being cleaned.



Not perfect, but absolutely good enough and way better than it was.

Aside from looking tidier, having the carpet and trim in there does make a huge difference to the noise levels. The boot seems to act like a big resonance chamber without it in.

I had planned on swapping out the plugs for a new pair as the ones in there are the wrong heat range according to my reading. However the cross referencing for the right ones apparently didn't work as the plugs that turned up are too large a diameter to fit. Need to double check my notes and whether what arrived is what I ordered (this was an eBay seller so that's not guaranteed). That's a job for future me though.

For now I've checked the tyre pressures, fan belt tension, and that nothing seems in any more imminent danger of falling off than usual, so that's probably as far as the prep work will be going. Trip is only sixty odd miles but it always seems longer in my mind because I only do it once a year I think.

Wonder if I'll end up parked next to anything interesting in the car park this year. These were last year's contenders.





That P4 is definitely going to be one of those cars I always look back on fondly. Definitely one of those cars which I reckon is drastically under valued in the classic circles, and I'd definitely not discount owning another one one day.

[CitroJim]

Do enjoy a great weekend away Zel The difference in the boot carpet is quite remarkable!