Do you have to pull the engine on a 1991 300zx to pull the wiring harness through the fire wall?

No, you typically do not need to pull the engine to remove the wiring harness from a 1991 Nissan 300ZX. The wiring harness can usually be accessed by removing the necessary components and connectors, allowing it to be pulled through the firewall without engine removal. However, this process can be complex and may require some disassembly in the engine bay for easier access. Always consult a repair manual for detailed instructions specific to your vehicle.