Dean's Activa/XM/V6 and now Talbot blog

[Deanxm]

Hi Jim

Yes the vac advance does move when I suck in the pipe, and it holds a vacuum no problem.
I think I have Sussex how it works with your guidance Mike.
The bottom fingered disk spins with the rotor shaft, an the Balkans weights advance the plate in relation to the rotor, the vacuum advance plate with its 4 fingers sits above and is stationary but rotates when vac applied, this must shift the magnetic field as it moves, this sends a pulse to the ignition amp to give timing and also handles dwell on its own.

I think a lack of sleep addled my brain, that's my excuse anyway

Mike I know what you mean about vac advance requirement for low performance motors, this one has a fairly low compression ratio and not much power so would guess it is not likely to knock due to lower cylinder pressures but it should move a bit and also not have to be static timed 16 degrees btdc instead of the specified 8 degrees to be able to drive

[white exec]

The vac advance must be moving the whole internal mechanical assembly, weights mechanism included. This will add any vac advance to that brought about by the centrifugal weights. The part that stays still is the coil-pickup, with the rotor arm just going round in the centre of it all with engine revs.

Do like the bit about Sussex and the Balkans.

[Deanxm]

Damn autocorrect!

Can't remember how far I got but more has happened and improvements have been made. The main issue I came up against was that the cooling fan packed up, the fan worked and so did the switch but the radiator want getting hot at the bottom, then she started getting over 90c when going up hill, I suspected a failed waterpump and sure enough, on removal the impeller was no longer attached to the shaft. Fitted a new water pump, belts and other little bits like selector rods to improve gearchange and another engine mount rubber for the same reason and I have further improved running (and heater).

Still a bit of hesitation between just off idle and half throttle so I think I will have to strip the carb again.

keeping an eye out for a new carb or one that is known to be a Solex 34pbisa 16 as since mine has no markings, and no I.d tag, it is nagging in the back of my mind that it is either the wrong carb or jetted incorrectly. If one comes up cheaply I think I will go for that and try it.

The next installment later this year will be of the rust massacre, panel fitting and paint job, looking forward to that very much if only to get all of the new body panels out of the shed!

D

[white exec]

Did find these folk, by googling 'Solex 34 pbisa'...
Eurocarb Ltd, Pangbourne
They do a complete service kit (incl 160-size jet) for Peu-Cit.
Site comes up as www.dellorto.co.uk

[Deanxm]

I did refurb with a service kit and I do have the 160 size jet but this jet is actually the float bowl fill valve operated by the float, the old one was a 160 as well and worked. The actual jets are not market which is odd because how would you know what size you are fitting? Unless using a gauge to measure the jet size.

I was advised while talking to carb doctor that the Solex fitted here was always a bit rubbish and that a single barrel Webber would be a good upgrade but I refuse to believe they rolled out the factory doors with carbs that didn't work, unless anyone knows better and has first hand experience?
Every recommended 'upgrade' on these vehicles I have found is completely unnecassary and if fixed correctly with original parts there is no issue at all, spring assisters is one I am wrestling with at the moment, many firms will sell coil or air assisters for the rear leaf springs at a special rate of about £350 and they are raved about, but I just don't see the point, why not just fit updated 5 leaf springs to replace the old knackered ones saving you enough money to replace the shocks as well for the cost of an assistor kit?

Anyway, thanks for the link, I will look into them.

D

[white exec]

Citroen at least didn't always get it right with carburation. BX16TRS was notorious for a substantial flat-spot at half throttle or more, where the engine just 'yawned' and would only pull away if you eased up on the throttle. There was also hesitation on light throttle. This was finally sorted on ours by the dealer, who fitted a set of Peu jets (for the same engine!) - apparently Peu had tuned their heavier car differently to the lightweight BX. The new jets transformed our '91 BX's performance, at a 2mpg penalty, but well worth it.

Just wonder whether something similar could have happened on the Talbot front?

[Deanxm]

It could have Chris, it will be worth looking into in the future but for now i seem to have cracked it to the point where it is driveable and feels pretty good. After fitting the new water pump i can now drive off within a minute of cold starting and take it off choke as soon as i am on the move, the flat spot has also nearly gone, i believe a lack of hot coolant to the carb due to no water pump was causing issues.

The next step was to re-visit the ignition timing, Talbot say in the manual the timing should be retarded 4° when running unleaded which i sort of did but when looking into this on many an old knackered car forum they all seem to say the timing needs to be advanced when running unleaded so it is now set to 13° BTDC and it feels very much more lively and responsive with the flat spot all but gone so i am pretty pleased with that. There is now a slight 'Yawn' when rolling into the throttle on the open road sometimes which i feel must have been there before and was masked by the flat spot but this must be a carb issue, for the moment it is very driveable though and with the weather improving i really start looking at sorting the rust out before it all turns to air.

D

[white exec]

I think it's the octane rating of the fuel that could mean IGN timing would need changing, not whether it's leaded or not. Wonder what rating your engine was originally designed to run on?

[Deanxm]

4 star which was something like 98ron? Manual states 10 degrees btdc for 4 star and 6 degrees for unleaded but at 6 degrees it's very course and feels like it's fighting itself, 10 degrees feels ok and at 13 degrees btdc it is much livelier and pulls better lower in the rev range

[white exec]

Maybe a rolling road is the only way to get the answer - or lots of trial-and-error!

[Deanxm]

I was going to write a lengthy update but tiredness and a lack of time dictates that I just do this

[Deanxm]

After a great deal of welding, parts, painting and labouring the dampervan has been returned to her former glory...

[Deanxm]

Well, another two years goes by…
I hope everyone is keeping well?
The XM is still happy and used regularly apart from the heater blower resistors that packed up this weekend. The Talbot is still with me and has just undergone a stage 3 spruce up with new door bottoms welded In, panel seams smoothed out, bitumen insulation added (huge difference in road/wind noise), new roof lights, led lighting and Dynax cavity wax (definitely closing the gate after the horse has bolted).
They are both, surprisingly (touch wood) very reliable and the old camper is damn near indestructible, something it arrived with broken gets fixed, and it stays fixed, nothing short of a miracle, anyway, gratuitous photo’s just because.

[white exec]

Dean! Great to hear from you!

The camper looks tremendous, as it should do after all that work, and good to know the XM still in good shape too (apart from the blower).
Hope all's well with you. Your posts much missed, but I think you've been busy.....something has to give!
Atb,
Chris

[Deanxm]

Good to hear from you too Chris, I know furlough and it’s aftermath has been no joke for many, but since last March it has been so busy at work, a couple of weeks off would have been welcome

Regards
D