MatraSport Forum

General Matra related => General Discussion => Topic started by: Lennart Sorth on April 02, 2017, 10:59:03 pm

Title: Matra lives again ! ... well MINE does ... :-)
Post by: Lennart Sorth on April 02, 2017, 10:59:03 pm
Hi all,

After having neglected my lovely Murena for 3.5 years, while I was rebuilding my new house, I today FINALLY found time to give it a little of my time.

The engine has for over a year not been able to get started, due to lack of ignition - something that previously was an intermittent fault, now become permanent.

I soon found myself focused on the 6-pin connector in the passenger-side of the front, leading to the back of the car - and found several of the pins badly corroded, to the point of almost not making any connection at all !

I put the connector itself into the dishwasher, which left it looking BRAND NEW :-)

All the threads in the wires looked fairly sad - some almost black, so I applied the trick I had read about on the Internet : Vinegar saturated with salt - and stuck the exposed wires in there for 10-15 minutes.  This actually WORKS, - and the wires came out looking shiny and NEW !  - a quick rinse in baking-soda dissolved in water neutralises the acid, and I set about putting new pins on, and assembling the connectors.

Then I - tentatively - tried turning the key, - and lo and behold, the trusty engine came to life as had it just been going yesterday ! :-)

This made me very happy of course, and I now feel the the loooong list of "remaining things to be sorted out" is MUCH less daunting, now the heart is beating ! :-)


Regards to all of you !


Title: Re: Matra lives again ! ... well MINE does ... :-)
Post by: Lennart Sorth on September 16, 2017, 05:55:33 pm
Update ...

as so often with an old car, I *thought* I had found the reason for unstable ignition, but Roy
pointed out that there shouldn't be any direct link between the 6-pin connectors and ignition,
- even if there is a fat 12V supply (which was very corroded).
Roy instead pointed me at the ignition lock, and as always I believe he was right - once I got
the thing out of the car I could first of all see that one of the leads coming off the lock was
scorched and when started to attempt to measure its workings, that wire simply came completely
loose and fell out of the connector.

And this was indeed the ignition wire !  

The other is for cranking, and that seems to work just fine.

I have already treated the otherwise very tired and corroded looking wire with wonders of a
saturated salt solution in vinegar, - and the de-oxidising process stopped with a rinse in a
baking-powder solution, hence it looks fairly clean on the picture below.

My next challenge is to figure out how this connector on the ignition lock comes off, so I can
redo it.  



Title: Re: Matra lives again ! ... well MINE does ... :-)
Post by: Lennart Sorth on October 01, 2017, 02:49:54 pm
I  managed to get the connector off - and after staring in bemusement on the innards, I finally understood vaguely the details of how it worked. It is a funny construction - it reminds me a little of the timer-unit in my parent's washing-machine back in the mid sixties ....

The connection between the different poles is achieved by L-shaped, spring-loaded anchor, which is moved around - all of this fell out on the table as I took it apart, so I bneeded to figure out how it was supposed to be assembled before undertanding the workings.

The centre of this L-shaped anchor rests on the 12V feed, and the spring-loading should make it slide over the contacts in the periphery - first only ignition, but when you turn fully, the starter motor unsurprisingly get a feed too.

I gave the whole thing a thorough bath in the MAGIC saturated salt-in-vinegar solution - which completely removes all the oxidised  surface, and the saturated baking soda solution then stops further reaction. Then a quick rinse in clean water, and all copper looks like new again - see :

Assembling the connector was a bit fiddly, as the tiny spring is loose, but I dabbed a tiny droplet of superglue on it, so the L-shaped lever and the spring was one unit (for now) - then it was just a matter of figuring out how to align it properly with the lock barrel, but after a few attempts, I got it right, and the ignition lock tested fine using my multimeter.

Back in the car it works just fine - actually consistently switching the charging lamp on when the ignition comes on - this was one of the observations I had made before.

Slow steps, but always nice to have done SOMETHING for the old girl :-)