ok, i have a 90 civic base model hatch with a PR4 ecu/b18a1 swap. the ecu is throwing a code 4 which is CKP or crankshaft position sensor. my friend wired it up for MPFI. it has a brand new distributor on it and we switched the distirbutor wires that run to the ecu and the code kept coming back upon startup. anyone have any ideas on whats wrong?

upon typing this i recall something about needing to reset the ecu after changing something that caused it to throw a code...is this true?