Guys problem solved , one day I've accidentally removed the power from the mpguino before it saves to eprom and every configuration lost, so i've entered pulses per speed and micro sec per liter that and forgot configure vss delay that was 2ms by default
oooodd... Speed is now right except when i run over bumps and potholes (all the time Greek roads
) , then speed goes instantaneously nuts... That maybe is not a big issue...I'll try your solution, i have a lot of spares from power supplies so...