just brought a esc turbo with zetec conversion running fiesta turbo ecu got problem with rev counter not displaying correct rpm could this be down to the fiesta managment or just a dodgy rev counter itself

 

Is it showing like half or twice what you expect?

 

may be not even half not seen it about 2000 i dont think

 

You could either get a later tacho from a mk4 EFI car or dick around with the edis module to get what you want out (either by hooking directly into the tacho output on it or by playing around with the low side coil signals and some diodes - i cant remember what the erst tacho wants to see, i think its one pulse per revolution but not sure)..