SNAIL

Martin Igelmann · Posted: Mon Feb 23, 2009 9:26 pm Post subject: VISA: reliable ignition sensors

Hi all,
Due to the engine swap of a VISA V06/665 engine into my FIAT 500 I had to deal with the *'&%@ ignition sensors.

Apparently sometimes the sensors tend to fail as soon as they leave their "natural environment". The failure of the sensors has been a subject of many discussions in the German 2CV forums.
My guess is that the sensors are "killed" by voltage peaks.
When I started to test the engine in the FIAT 500 these sensors made me mad!!. Sometimes they worked for half an hour and then "poff": no function!

My solution was the use of industry proximity sensors that have the same funtion as the original VISA sensors. The industry proximity sensors however are much sturdier than VISA sensors. They are working at voltages between 10 and 35 volts. Their protection class is IP67.
The sensors I am using are from the German company ifm-eletronic in Essen.
Their designation is IE5099 / IEC3002 BPOG.

At the output lead I have put a 6V fixed voltage regulator (78xx, 79xx). Without this regulator the output voltage of the sensors would be around 11V.

The problem to use these M8 x 1 sensors in an VISA / 2CV enviroment would their small diameter (8 mm as opposed to the original 12 mm)
If you want to use them in your VISA/2cv you would have to search for M12x1 sensors. But then again you have to make sure that the timing is exactly that of the original sensors (attach marking at flywheel/housing with the old sensors before using the new ones).

In my case things were easier since I can move the position of the sensors in a slot of the adaptor plate. Perhaps you can manufacture something similar for the 2CV / VISA.

A word concerning the idling switch off valve of the DMTC 32/34 WEBER carburetter: I replaced the valve by an M6 Allan screw of the same length.
In my case the valve was not working properly and therefore this was the second reason why I had troubles to start the engine after mounting it in my FIAT 500.

But for the rest: I have been using the industry sensors for more than 4 years now and have done more than 40.000 km with absolutely no problems.

Best wishes
Martin
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