BX excess, can it be a success?

[Thread Bear]

A month later than planned, due to crap weather as much as anything, the 16 TRS Auto is going on the road as of tomorrow.
The main hang up was an inability to get the carb to work correctly. After having good study of what was there, and comparing it with any information published, I gained enough insight to find appropriate data. One achievement was to eventually find the Weber ID tag hidden under a load of gough on a top clamping screw. This revealed part of the problem, once cross referenced. The Auto has a different carb to everything else. Clearly the carb had been visited in the passed and hence the tag moving to where it was unseen after complete assembly. Hence the incorrect order of assembly of the levers controlling the carb. Not to an extent of not working, but I suspect its high speed performance was compromised, as it was starting to close one choke as the other came to more power.
The main issue for good running, however, was what Haynes, in a remote diagram, calls port 6. This was spotted by my mate just as was getting ready to pull the whole thing off the car for an evening rebuild. This is a bleed valve at the bottom of the anti flood diaphragm, which on this carb has a large black canister attached to it. In effect it is analogous to a suspension damper. Like on SU dashpot oil way, it slows movement, here preventing flutter and speedy motion of the butterfly valve. When port 6 is blocked, the effect is to part open the butterfly, and the tick over is set to about 1,600 revs, automatically, no matter what you do. To clean it requires one strand of auto multi-core 3 amp wire. A small hole indeed. Done the engine was much more biddable and having settled for a tick-over of 900 revs, its a but lumpy still, the car awaits some use to bed everything down before a re-tune.

I also had cause to rebuild the airfilter box. The centre fastner was mounted to low in the body. This had seen off the lid the car arrived with. Its a poor design all round and even with the centre fastner extended and washers to spread the loading the replacement looks pretty stressed to maintain a good airtight fit. I think any BX with this set up in use for a long term would benefit from a better constructed inlet tract and filter. Not simple as the carb is to hard against the bonnet and should have been a sidedraft. Air might be a low density mass, but it still does not do tight angle bends efficiently, It has to negotiate two here, not including the warm/cold air selector. Still I will go with the flow, or lack of it, for the moment.

A test drive now found the the car was quiet, smooth and changing gear in a much more sensible way. It is also considerably quicker. So I might not sell it after all. Only use can tell.
Still some fiddling about to be done, but stuff that is not urgent and should not effect road worthiness. No doubt something will fall off, but thats old cars.

[Way2go]

Sounds a good application of the grey matter there TB. Good to hear too that the cars future is now more assured with you.

[Tinkley]

Although I don't have the Weber on my car, I did at least correctly surmise it was an 'auto choke' issue. Glad you nailed it. On my Solexs' the main issue was the flow through the autochoke 'black box' and the internal diaghram especially replacing the one with the L shaped metal rod on it. This is the one actuated by the waxstat. The rubber hardens so it no longer behaves as originally designed. Massive difference on cleaning the fuel ways in this area out and changing said diaghram.

I'd be interested to see what you think of the car balance compared to the heavier engined diesels. Although the 1.6 is hardly a mega spritely beast it has enough power for its weight in my opinion and feels OK at least in manual form. Yes I have driven the diesels and they feel a touch front heavy although still very reasonable. I've not tried an Auto - at least not yet.....

Other than rubber perishing issues, hoses, wishbone bushes, suspension returns and maybe flexy front brake pipes the ca should be OK as far as I can tell. Mainly these are just old age related things which all cars not just BX will suffer from. At least with such low mileage rust should only be a very minor issue!.

I think you may have the early type round air filter. The later cars have a rectangular clip together box and different feed to the carb. It might well be worth changing it over as the later type does seal OK and is a piece of cake to work on.

[Thread Bear]

I believe the car is an early Mk2. A better airbox might be worth looking at. I can keep the original with the car.
The carb is still not set right as the cold running is wrong. That will be my mucking about with it trying to understand what did what. I will live with it for the moment as it really needs to be run for a bit to clear itself out. I might look in the scrap yard for an AX or later carb as an experiment.

Cannot comment on driving yet. The diesel will drive differently of course but both cars are on new spheres all round. The TZD Estate is more ponderous and feels more like an BMC 1100 to the TRS which really glides along. It has some shite tyres on at the moment so handling is not good. Now is that ride due to low mileage, or better balance?
Sadly being an early car it has uncoated LHM pipes. I need to go under and grease them up. Dr says no! Reliability says yes! Be nice to change the sunroof but I have no dry area to perform that trick at the moment. I think those tasks will await the next BX to hit the road.

[Tinkley]

The earlier cars have galvanised pipes AFAIK, at least my '88 did and the 91s' have the later and better black coating. I'd be more tempted to put a good coat of zinc paint on first prior to any greasing. In fact I did have one pressure pipe fail at about 150k on that car. None on the newer one 'til the rear subframe got remounted after welding up the mounts.....

Main area of high pressure pipe weakness appears to be the bit where they run over the rear sub frame btw.
Although I think my old 14 burst one of its pipes along the straight run under the car. The instant the pressure regulatot went into overdive I knew it was maybe a puncture, but the sinking feeling let me know it was all the suspension! At least I limped it about a mile home on locked out low at 5-10 mph....

[Thread Bear]

Quite a mileage covered today. Only just made it to the filling station, followed by a curious Police car. He was happy to chat, as the morning's purchase of the tax disc came up on his banger check. I told him it was filling with fuel, and then off to my chum at the garage to see how it was working when I got there. He knew my bud.
So a chat and a cup of tea with Mick. The tickover had gone back as before by now. So another poking session on the port 6. Then off to the scrappy Nr Wantage, only to meet the same police car! He asked if the test drive had failed! Cheeky bugger. Gotta laugh though.
Nothing much to move the BX on there, but I did stock up with other stuff and some antifreeze.
Having proved the thing was functioning it was a blat along the Icknield Way at the base of the Downs to shakedown the handling, suspension etc, in a more testing environment. Yet never that far from home, in case of problems. Thus taking me to Swindon, more parts and bulk dog food, accompanied by more interested Police cars, who each drifted off once their computers confirmed legal status.
By the time I got home the tick over was gone again. So I need to give this part of the carb a thorough cleanout. Another go at flushing to see if there is anymore crud to come out of the water system. No signs of overheating, nor of the fan going on. Before it was, so a worth while exercise in prevention. The ride is great, the tyres better than I expected and the brakes are back to better than most other cars. The seat is not as comfortable as my TZD one, nor does it adjust as far. Got all window functions back. But washer needs a clean out.
So it remains as to if I like Auto. Well if it remains like this, no. Its like driving with Bagpuss doing the gear change. Not a lot happens till things get desperate, then there is lots of excitement as there is a flurry of gear changing, before sleepy time again. Indeed unless you wave the accelerator pedal about the car will nearly grind to a halt on a hill, rather than change down. Likewise it will rev pretty high before finding a higher gear. Having the carb up the creak cannot help, but I am sure gearchanging should not be as random as this. Also I have yet to change the ATF in the gearbox. That may well be an issue. Maybe I am just to used to the diesel torque which happily plods along without need to move the accelerator much. By not moving the peddle enough I am not offering enough clues? But its not my style of driving, which is 'momentum' driving - that is good average pace, good road positioning and forecasting, using handling. If I wanted foot exercise I would drive something more sporty.
Still we are not there with a sorted car yet so its to early to condemn the Auto concept.

[Way2go]

re autobox, it sounds as though you have problems in the valve chest as the BX auto changes are usually slick & smooth. However, if the kickdown cable has been played with while you were adjusting the carburetter then that will also give problem of running/demand changes. Correct adjustment of this cable is critical to more than just kickdown.

[Thread Bear]

A possibility, but on being driven by an independent person, forget who, prior to purchase it was reported to be driving OK. I have taken care not to mess with the kick down, or any other settings outside those I could referance. The issue of tickover is down to the butterfly choke. The fault I found was also on this. Maybe it is not a fault, but I have not seen a carb where the choke starts to close at full throttle. The way I have it now looks more logical. Of course it could be me.

[Tinkley]

You probably also have the problem that the Auto is I belive only a 4 speed box. So 4th on yours is 5th on the manual like mine. On the 14 basic which had 4 speed manual this made it very unfriendly especially if towing - even a light boat/trailer!. The 5 Sp manual box is good on both the 14 and 16 in terms of ratios and torque. So manual gearchanges would be at anything from about 2,000 rpm upwards, with smooth running on the flat from 1500 in any gear. Of course if you keep it over 3,500 rpm all the time it will move at a respectable pace for an old'un...

On the manual with Solex you can feel the second choke coming in around 3,500 depending a little on gradient. Quite decent torque there even on the single choke. I had to fractionally adjust the tamper proof screw adjusting the second choke opening on mine to smooth transition at that point. Only moved the screw about 10 degrees (from factory setting), enough to help it.

If you have a similar waxstat driven diaghram in your Weber, replacing it would be a good investment. Check the waxstat moves freely too. BTW manual choke conversions are still available too. Pages 118-121 of the Brown Haynes manual gives quite a reasonable ammount of stuff on dimensions for setting the choke openings. At least you get a starting point. When I found my last car had the float level over 7mm out and you knew someone had tampered, removed springs etc.....

[Way2go]

When 4th gear engages, the torque converter is fully bypassed. You will find that it only engages at a rising speed of 42 mph under a light foot and wiill drop out when your speed falls below 38mph.. A heavy foot will delay the 3rd to 4th change beyond 42mph.

[Tinkley]

When 4th gear engages, the torque converter is fully bypassed. You will find that it only engages at a rising speed of 42 mph under a light foot and wiill drop out when your speed falls below 38mph.. A heavy foot will delay the 3rd to 4th change beyond 42mph.

Which would equate to about 2,000 rpm or a little over when in top. Sounds about correct selection, allowing for inclines, but still makes 3rd to 4th a bigger step on the 4 Sp box than the 5 Sp manual. It does appear that the 1.6 Auto seems a bit underwhelming unless very lightly loaded, making the 1.9 a better all rounder, though I've not driven either in auto version.

[Way2go]

Ah, missed the 1.6 bit and comments apply to the 1.9. Not sure if there will be differences here on the 1.6?

[Thread Bear]

Taking on board info gleaned and given todays session, while time consuming, it was most successful. I now have a far more tractable car, with tickover bang on. Water chucked out more poo, but I decided to go with the antifreeze this time. The ATF was disgusting, and I am sure, adding to the problems of messing around with carb, and some years lack of use. Oil changed with filter. Due a short change in a few thousand miles. ATF again to, since you cannot get it all out in one go.

The test drive had the gearbox behaving itself pretty much. It certainly kept up when I gave it some beans. Sadly the handling did not, so we had a slightly sideways moment on a damp patch. Need to shuffle some tyres round. So we are on the right track. Not perfect, but a B plus, I think. I can live with this and I think there is more to come. Test tomorrow will be to see if cold tickover is correct. Also the replacement speedo cable has never been connected. Its clamped in the wrong place. So that will be the miles of 28k recorded and another 18k not. Most odd. Hopefully put in place it will work, as I can see nothing wrong with it. So the car is as advertised by chap in Blackpool. Just wanted some extra love and attention.

So rewarding myself with out of date Vanilla Slice and real coffee.

[Way2go]

ATF? I hope you used/mean Dexron2 ?

[Thread Bear]

Indeed so. All covered in another thread. Surprisingly cheap.