I have read that it means crank angle sensor as well as crankshaft postion sensor.
I have replaced Distro and still get the same code 4 on a 90 civic.

Is there a Cranshaft position sensor elsewhere on the vehicle that I need to change?

Problem is Check engine light, with a code 4 when I cold start. Rought driving over 3000 rpm and sometimes it will jsut kill the engine. After driving for 10 mins, I can shut off ignition and turn back on when driving and it clears the CEL and code. Related to car being warm???
When cold, I cannot get it to go away, even with a battery disconnect for 10 secs.