turn the key , hear the relay but a split second delay before starter

[Tony H]

Weird thing. Normally you turn the key and you can barely hear the Relay because teh Starter kicks right in. The other day I turned the key, Heard the Relay (sounds like it's right in the middle of the Firewall) and nothing for a split second then the starter cranked fine. Any thoughts?
Battery is good. I had the connections off the Starter 3 months ago, so they were put back on correctly and tight.
From looking at the paper work from the PO he had a NEW starter put in less then a year ago. Are Explorers known for gumming up the Bendix gear?

 

[Opera House]

There is a solenoid plunger that pulls in the gear prior to rotating the motor. Chevy had this problem with water getting in the solenoid and freezing. Operating the key would melt the ice and then it would work. Have never heard of this with this starter. I have had intermitant solenoids on the fender but have never seen these cause delayed operation.