ok heres the down low, the car is a 90 civic hatch, b16a swap, dual point converstion to multi, the engine is odb1 i coverted it over work in odb0, switched intake manifold and such, i have soldiered all my connections and rechecked them, all the grounds seem to be good except for the under dash grounds i haven't really checked them honestly,but, heres the deal the car runs great no check engine light , the dash tach gauge has a strange spike to it, it will be fine at idle then it just spikes up to 1200 rpm or drops down to 400 rpm but the cars idle or rpm doesn't change, its just the gauge that does, i also hooked up a fields vtec controller to get rid of my speed limiter but the rpm on that will go crazy, it literally goes from an accurate reading of 700rpm at idle to 8300 or even 8900, but the cars idle never changes, i've tried changing my dizzy, my ecu, it has new plug wires, new cap, rotor.... the car runs super but does have an odd stumble or hesitation at 2300 rpm to 3000rpm, then is fine, anyone have any suggestions, thanks ahead for any input, also doesn't feel like vtec really engages, its just odd........hmmmmm

 

its a wire problem.. hardwire you tach for good connection

 

yes but the fields vtec controller is running right off the ecu where i spliced in? i don't know its just odd....i'll try to run a direct line off the dizzy to the tach but.....anyone else with any suggestions?

 

make sure the VSS plug is connected securely, I had a similar issue when I did my B16a swap, VSS sensor connector was loose

gl

 

check your blue wire off the dizzy follow it down through the harness make sure its not slightly severed

 

This kind of problem has traditionally been solved by changing the igniter or the coil. Do you know for sure that the distributor that you tried was fine?