Hi,
I have 91 Fleeetwood 4.9 V8 that stalls at low speeds. I read somewhere that the problem can be fixed by removing some valve or fuel flow adjuster in the gas tank (or along the fuel line).

Has anyone heard of this?

Thanks

Ses light on?, Has battery been disconnected?

I've had the wires/plugs changed, work on the rest of the ignition system, used 94 octane gas with system cleaner and injector cleaner. New battery in car also.

Sounds like you may need to relearn idle. Also check for codes.