91 CRX Si Tach issues

Hello all...I have a 91 rex si with 68K miles. I have had continuing problems with my tach. After the car is warmed up the tach needle reads 0...bottomed. Sometimes it feels like it wants to stall, but it never does. I have addressed this as an idle problem, but I have tried everything, ie... new dizzy, new eacv, new plugs, wires, air filter, fuel filter. I have check all vacuum lines and there is no leak. I took it to a Honda dealer and they say its the tach not reading right...cause my ignition timing is dead on spec. If it is the tach do I have to replace the whole cluster? I don't understand how it can be my tach if it reads correctly until my car warms up... Any insight or tips would be greatly appreciated. Also, I just installed a B&M short shifter, and it seems hard to get into gears...It was a little difficult before the short shifter. Any ideas on what I could do....THANKS!!!!

Bump

If its hard to shift then try loosening up bolts that hold the shifter to the linkage a little. When I first put my short shifter on I made the same mistake and it was hard as hell to shift. I lubed everything up and loosened the bolts so they wouldnt bind up but still held everything together and now it shifts like buttery smooth with very little effort at all.

My tach does the exact opposite. It doesn't like to work when it's cold... takes a few suggestive taps to the cluster. It really is a pain. If your car is running right, maybe undo the cluster and see if the tach connections are right. The tach signal to the dizzy is the blue wire so check that and follow it as far as you can.