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BEC Speedo sensor position
Andy W - 8/10/11 at 04:28 PM

Since I have my car on the road I've had problems with speedo jumping. a thing that's made worse by have having a digital speedo which response is instant. I may be driving at 40mph when all of sudden the speed jumps to 60mph then it may be ok for while. I have the sensor looking at the threads which extend through the prob adapter. I've put the jumping down to picking up another signal from the prop adapter and have moved the sensor many times, closer & further away till it no longer works. Today i decided to try and cure this once and for all. I have had a steel disk with four lugs on it made to fit inbetween the prop and diff. After the lug passes the sensor the sensor has nothing to get another signal from, just fresh air. However when I've tried this the speedo jumps more than ever. The only thing I can think of, is that the lugs are to wide and the sensor is getting more than one signal? The lugs are 10mm wide i'm tempted to cut them down to about 3mm? has anyone else had problems or got any ideas


Thanks Andy


daviep - 8/10/11 at 06:04 PM

I run mine as per yor original setup, I turned the end of the bolts down to 5mm and they stick through the adaptor about 10mm with the pick up looking at the last 5mm. Not had any probs.

Are all the connections made properly and clean? Wiring not running near the coils or anything else likely to be producing interference?

Is the sensor bracket nice and solid and mounted to the engine?

Sorry I cant be of more help.


needforspeed - 8/10/11 at 06:07 PM

sorry if i sound ignorant but have people tried it on the prop before? would of thought there would be quite a lot of movement in the prop backwards and forwards if you let of the throttle slighly?


Andy W - 8/10/11 at 06:22 PM

the bracket is solid,
I'm now wondering if it's the speedo healer playing up. I might give it a run with it disconnected


Andy


daviep - 8/10/11 at 06:30 PM

quote:
Originally posted by needforspeed
sorry if i sound ignorant but have people tried it on the prop before? would of thought there would be quite a lot of movement in the prop backwards and forwards if you let of the throttle slighly?


Yeah it's quite common, shouldn't be too much float on either end of the prop.

Davie


Proby - 8/10/11 at 07:16 PM

I run mine off the propshaft flange. I had to modify it slightly recently due to it not working correctly, but after some slight adjustment, it's working superb. My next plan was to do pretty much the same as you, fit lugs behind each of the four bolt heads on the prop flange adaptor. Depending on the type of sensor/trigger you may have to get pretty close to work well. My proximity sensor is literally 1mm from bolt heads, set up using a mirror and feeler gauges! Works a treat now though. Good luck sorting it.


mad-butcher - 9/10/11 at 05:43 PM

4th reply from bottom http://www.locostbuilders.co.uk/forum/3/viewthread.php?tid=156699

tony