The starter on my 1992 Tempra has started turning the engine over slowly at times. Sometimes it refuses to turn at all until I have turned the ignition key a couple of times.
It's not the battery, I fitted a new battery recently and it's got a good charge. The voltage dips down low as though the starter is absorbing power, but not turning.
Is it likely to be the brushes? My only past experience with this was when a starter on a Granada would either work, or not, and when it wouldn't, a bash with a hammer would cure it.