S0 Fuel System, VQ35DE

The CJM S0 Fuel System provides everything required to convert your DE 350Z or G35 to a true return-style fuel system with a manifold-referenced adjustable pressure regulator.

A properly designed return system is essential for maximizing fuel pump and injector performance while delivering safer, more consistent tuning—especially under boost. By referencing manifold pressure, fuel pressure rises 1:1 with boost, maintaining stable injector differential pressure and improving overall reliability.

The S0 system retains the factory pulsation dampers for excellent drivability and smooth part-throttle operation. The OEM 5/16" feed line and factory fuel rails remain untouched, preserving factory routing and simplicity.

Return fuel is sourced using the CJM 6AN Fuel Tap, installed between the rear pulsation damper and the driver-side fuel rail. From there, a -6AN PTFE hose routes fuel to the adjustable regulator inlet, and a second -6AN PTFE hose returns fuel to the fuel pump housing.

All external hoses are PTFE-lined with stainless braid and crimped hose ends for maximum durability and fuel compatibility. The tank return line features a black PVC coating to prevent abrasion against surrounding components and wiring.

The system also includes our Return Correction modification—a critical upgrade to the fuel pump assembly that properly converts it to return-style while preserving the factory in-tank venturi system. Without this modification, the pump would be unable to scavenge fuel from the left side of the tank, leading to potential starvation under low-fuel conditions.