I bought an 88 RX7 convertible from a guy in Ontario. I flew down to pick up the car and drove it home, 1000 miles, no problems.
I drove it around home then went out to Alberta. Everything fine.
When I was in Alberta I gassed up at a Petro Canada gas bar one morning and about 10 minutes later the car started misfiring, then would clear for a while, then misfire, all this at speed.
I had a problem years ago when I picked up some gas with water in it.
Is there a strainer or filter on the fuel pump? I changed the fuel filter in the engine bay.
I suspect the fuel tank needs draining, that is elementary. Is there a screen on the fuel pump pickup, if so where is it and hoe do I get to it?
Thanks,
Mike

 

It's a common issue with the FC that the fuel sock will become dirty and cause the car to bog. Does it also by chance bog when your turning left around a corner?

If so, then you probably just need to clean/replace your fuel sock. You can get to it from a opening in your hatch underneath the carpet.