92 Z34 runs rough / stalls

Greetings,

Problem ... car will sometimes start and run fine or run at very high rpms and rough with a strong gas smell when engine cold. When car does run fine, then after engine has warmed up, turn off let sit for a few minutes try restarting, will run eract, rough and stall. Only way to restart is the push accelerator down. When problem first start there would be a backfire when starting cold. Another thing if I move the wires on the connector to the sensor on the air cleaner I can make the car rough and stall. Also when I try to recover the diagnostic codes all that is reported is code 12, also sometimes when trying to get the codes the ses light will flicker and stop displaying the codes, there are no other codes displayed or stored.


thanks

brian