Complex sentence: The KLF, who were formerly in the charts as The Timelords back in 1988, had a huge club and chart hit with "What Time is Love?" which made No.5 in September which started a successful run of hits that continued through to 1992.
Split into simpler sentences: The KLF, who were formerly in the charts as The Timelords back in 1988, had a huge club and chart comeback with "What Time is Love?" which made No.5 in September. This started a successful run of hits that continued through to 1992.