Harvey, If your fuel pump was a piece of junk, there's no telling what it might do. The one I had that worked for 300 miles eventually started "acting up" where I thought vapor lock might be the problem. The engine started running rough, conking out, etc. when hot.
It was only after the second pump didn't work at all that I realized that either the cam was bad or the pumps were bad.
I tested the "original" pump, which was actually an Airtex re-man from 30 years or so ago that I was able to get the pump arm to pump fuel when I moved it manually. It was removed a couple years prior after the vehicle sat for a long time without being started. Ethanol had gummed it up pretty badly but even in poor condition it was better than the new ones.
You are now the 3rd person on this forum with an identical fuel pump story - 2 new pumps failed and cam lobe was suspected.
I think once you get the fuel pump problem sorted out, you'll be able to quickly determine whether there are other fuel problems or not. I'm betting not unless you have a dodgy carburetor.
It is immensely frustrating that new parts can't even be relied upon to work when brand new. It's hit or miss with just about everything these days. I've opted to rebuild old parts from now on rather than buy new parts. Even if I buy a new part just to get back on the road, I save the originals for future rebuilding.
My pump was rebuilt by Then & Now Automotive. Maybe they'll have good cores. Keep looking on ebay. They seem to come up for sale pretty often.
See if you can find the correct AC part number for the pump. There are a bunch for sale for other makes of vehicles which might be identical to the Chevrolet pump.
