Today I installed a new tank. The replacement tank came from a carby 240, so the pickup was wrong. This meant I had to actually address the rust on the pickup I had, which means fully tearing it down. Why not just buy a new pickup? Because they're expensive, because they're a single unit which includes the fuel level sender. As my sender is fine, I thought I'd just clean up what I had.
All that's required to tear it down is to desolder the wires for the sender and pump, and to open the press clips that hold the housing around the sender. Beware there is a small spring on the float arm hinge which you don't want to lose.
Results
The wagon still has a wonky idle, but all the knocking under load has gone. I'll dig a bit further to see if there's any obvious cause of the idle issues, but otherwise I'm happy. It's possible the underdrive pulley is maxing out the capabilities of the voltage regulator in the alt.
