Rev Counter issues

[Anthony]

Update.

 

Changed to Carbon fibre dash and new scuttle ( allowing wiper motor etc to be removed ) and carefully labelled all leads and replace then on re-assembly.

 

On starting the car and running the rev counter behaves erratically over 4000 RPM ie swings +/- 500/600 rpm( it is a Stack Clubman with 0-4000 on small scale and 4-10K on large scale ) and Stack advise it will either work or not !

 

The avoid issues with the loom, I have run separate cables new feeds to battery for + and - feeds and still have the same problem.

 

I have also tried a new coil, but to no avail.

 

Car seems to be running OK - ie no major mis-fire over running at this speed although, car is being checked in garage so no long periods of running other than to get water / oil reasonable temp before 4-5K check.

 

Car runs weber/alpha 3D

 

Anyone any thoughts

 

Many thanks

 

 

 

Anthony

 

X-Flow-power; the real way forward

 

 

[StewartG]

Try running the tacho directly from the -ve side of the coil, if it works ok you have a faulty webber alpha if it doesn't work properly you have a faulty tacho.

[Anthony]

Thanks Stewart,

 

The feed is coming straight from the -ve side of the coil for tach pick up ( +/- ve straight from the battery ) which is as simple as I can make it !

 

Thanks for your advice

 

Regards

 

Anthony

 

X-Flow-power; the real way forward