Get rid of the platinum plugs as soon as you can. They were not designed for this engine..go back to the copper ones h7dco! The poor spark that these platinum plugs produce cannot be handled by the 103 and 102 engines (no variable timing for starters). Everybody wants a modern solution for their cars but this is one situation where the old way is much much better!
Do a search on this forum you will get some more info. Hope this helps.