fuel in cooling system

90 Miata has strong fuel smell in cooling system already pressure tested system no leak already flushed system fuel smell returns no evidence of water in oil scratchin my head any ideas

Is this a rotary engine? What size and year?

not rotary
1.6L and its a 91 not 90

I looked at a system diagram and their is some solenoid valves and check valves starting at the top of the gas tank which returns vapors to the intake manifold so they are burnt. Check for a defective unit with vacuum pulling gas. I think during cooldown it pulls a vacuum and some gas vapors are sucked into the coolant. Vacuum will seek any leak as bad as a water leak.
You are aware no gas lines flow through the radiator unless sometype of aftermarket product is installed.