1992 Honda Accord engine light stays on/rough running

it takes approx 6-10 winds,then the engine will start with the ecu light remaining on, at this point the engine wont rev above 4000rpm.If i switch the engine off, then quickly restart it, the light will go out and the engine will operate normally. I have the lamda sensor replaced and had the ecu read, producing fault codes 4 and 8. i have been told that these codes are sensor faults located within the distribuor but am unsure of this. any advice or fix will be appreciated