Zel's Fleet Blog...Rover, Renault, Peugeot, Trabant, Invacar & Sinclair C5

[Zelandeth]

Been very little going on lately. Life has been busy leaving little time for car things.

A bit of numeric symmetry arrived today.



We ended up switching to a different brand of oil with the last tank of fuel on the Trabant, and it definitely doesn't like it as much as what I'd been using before. It's far more grumpy about idling - so I'll definitely be returning to the Castrol 2T that I had been. Only wound up with this one (think it's a Comma oil) as a target of opportunity while it was picking some other parts up. Will switch back with the next tank.

In old tech news, there was only one model left I had set up as a saved search set up for on eBay. The Toshiba T3100SX. With that I'll have completed the lineup of machines that my father used to bring back from work in the 90s.

This is a machine though which has been on the list for a while and I expected it to stay there as they generally fetch really strong money nowadays. Until one popped up with a £25 buy it now price. I'd barely even read the listing before grabbing it. Even if it turned out to be nothing but a parts machine at that price it was cheap.

It also turned out to be shipped by one of those people that think a couple of layers of the thinnest bubble wrap you can imagine and some brown packing paper are going to provide any meaningful protection going through the post.



I really don't quite understand what goes through people's heads when they post things like this.

Nevertheless it seems to have made it unscathed.



Normally I'd have been worried about the plasma display - however in this case I knew it was already broken.



I am 97% certain that I have a spare display panel for one of these in The Pile of Bits of Dead Toshibas in the loft from one I scrapped back in the very early 00s.

Have to wonder what stories this might have to tell. Definitely seems to have done a few miles.



I'm thoroughly expecting this to need a bunch of recapping to get the power supply up and running again. On the plus side if my memory serves me rightly, the HT supply for the display on these is derived by a pretty conventional inverter actually on the display driver board. This is good as it means that the main system power supply doesn't have anything awkward to emulate like a +295V DC rail for the display to handle. Unlike for instance the IBM P70 which is waiting patiently for me to deal with, with a dead PSU which does include the HT supply for the display.

Then like buses...hey look, another one!



This wasn't as cheap as the last one, but was still right at the bottom of the usual price curve of these machines, so I grabbed it. While it's significantly less beat up than the last one there are immediate signs that this is likely to be a parts machine.



Corrosion that appears to be leaking out from inside the machine doesn't generally bode well.



Crossing my fingers that the hard drive (which is just behind that rectangular cover) hasn't been wrecked. As seemed to be Toshiba's fashion around this period, these machines use a drive with an oddball interface rather than a normal IDE/SCSI or ST506/MFM setup. Equally annoyingly, they seemed to love using *different* oddball interfaces on each model. The T1200, T1600, T3200 and this all use totally different arrangements. The T1200/1600 at least do use the same actual interface, but the drives aren't interchangable as they're 20/40Mb versions respectively, and there isn't any way to configure things so the right drive needs to go in the right machine. I can kind of give them a pass when the T1200 was being designed in 1987, as 3.5" drives were still pretty cutting edge then, never mind something suited to stuffing in a laptop with automatic head parking and ability to spin up/down the spindle under power management control. However by 1990 when the T3100SX launched 3.5" IDE drives were pretty commonplace, so the logic seems more questionable.

While it may well be in far worse shape internally, one thing this has over the first one is an intact display.



Given the cover on the mounting screws is missing I do wonder if this has at some point had a replacement display. Either way there's no visible screen burn I can see at least.

It also has a UK rather than US keyboard layout.



I know I definitely have a spare one of these up in the loft, but not having to go spelunking to find it would be a bonus. Plus this one is far less worn than that one in the loft.

This one also came with all the original documentation and software which is always nice to have.



Only thing I'm missing is the external power supply. Which I'm not too surprised by to be honest given that they had a bit of a reputation for randomly going bang (loudly) and dying even back when these machines weren't all that old.

When I'll actually get time to get stuck into reviving this I'm not sure. Though I'd rather do it sooner than later as if the innards are being slowly eaten by capacitor and battery goo I'd rather put a stop to that. We'll see I guess.

[Zelandeth]

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.