Uninvited Gear Changes

December 2, 2004

I have just returned from a trip to central France in my newly acquired Lucy. It has been a very pleasant drive of around 1500 miles on fairly straight, fairly flat roads which were not peppered with potholes and used as storage space for traffic cones. Not like England at all! In fact, in several places, I was tempted to put my foot down. That is when I notice an annoying little trait my Lucy has.

Cruising along at around 70mph I occasionally caught up with a 2CV and attempted to overtake. Unfortunately, as soon at I twitched my foot on the accelerator pedal the darned car would kick down – dropping a gear and overdrive. I would be left revving the engine loudly whilst the 2CV disappeared into the distance. Very embarrassing!

Somewhere I read an article, on a web site or forum, that suggested the electronic kph to mph converter might be to blame for fooling the ECT control unit. Does anyone know if this may be true?

The theory kind of makes sense. If you are travelling at 70mph the converter reduces the signal so that the speedo reads 70 instead of around 112 which is your actual speed in kilometres per hour. But WHERE does this conversion take place? If the ECT is getting the same signal as the speedo – when you are travelling at 70mph the ECT thinks you are only doing 43KPH. If I were doing 43kph in top gear with overdrive and wished to accelerate then I can understand the transmission kicking down. The problem is – at 70mph it doesn’t need to. There is plenty of power for the Lucy to accelerate up to 90+ without the need for a lower gear at that speed.

The best way for me to test the theory would be to disconnect the converter. Does anyone know how to do this or even where it is? Can I maybe, just temporarily, disconnect one wire? If I can prove the case I will remove the darned thing and fit a new speedo face. It would be much more useful anyway as I intend to do many more trips to the continent and could do with a kph indicator. Incidentally, if the theory is correct, I expect that the fuel consumption would improve if the gear changes were retuned to normal. My wife has already started referring to my car as “juicy Lucy”.

Rick Hathaway.

December 10, 2004

If you remove the clock housing depending on how yours was done the unit will be connected inline with the cable plugging into the clock face housing there is more than one plug but you may find wires jointed and cut it, all you have to do is put colour to colour back how it was and change the clock face to a dual face clock reading MPH on outside and inner kmh, so what need is for convertor? or is it other way around either way you know what i mean, if you want instructions how to get out clock face ask because i aint writing all that if you know how.