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Problem on my engine 4g15

locking sound besause of
-distributor unit
-or underfiring at combustion/etc cycle

The scenario is
-when my car is underpower (cornering or wrong gear ratio) this will happen

Solution
Have cut the spring inside the distributor unit
-The sound disapper
But then after change engine(previously 4g13) to 4g15,the sound came back.

My concern is
Do i need to change the distributor unit or do the port n polish+top overhauled because i want to put powerzone camshaft...