Art, Dan, Phil, All,

The in-tank pump was wired correctly, and installed correctly - however there was one fatal flaw, self inflicted I must admit. I reused the rubber fuel hose from the pump to the sender assembly - the tube inside the tank. Well - that hose split so the pump pressure went partially to the main pump, but partially just recycled back into the tank!! The shop told me it was likely caused by the higher pressure of this pump versus the stock pump.

All I can say is, unforced error on my part.

The 2 big lessons for me:
1. Document when you replace parts & pay attention. I suspected I may have upset something when I was doing routine maintenance, but didn't make the connection.
2. Don't reuse stuff that you can easily replace, like rubber hoses/tubes, belts, etc. The pump came with a new hose, I don't recall thinking anything in particular about not using it, I already had the new one and couldn't send it back anyway. My inner Scotsman failed me.

Thanks for all the troubleshooting tips, hopefully others will learn from my mistakes.

Mike