Idle issues plague many SR20DET-powered S13 180SX builds, manifesting as frustrating stalling under boost, rough cold starts, erratic idle, or inconsistent throttle response. The Genuine Nissan Idle Air Control Valve Assembly (IACV-AAC, part number 23781-50F05 / B3781-50F05) is the factory-correct solution that restores precise airflow control at idle. This valve works in tandem with the ECU to maintain stable RPM across varying engine loads, temperatures, and boost conditions, eliminating the common SR20 problems that plague modified cars.
As a brand-new, never-installed OEM unit, it delivers exact fitment and performance matching the original engineering specifications. These IACV-AAC assemblies are becoming increasingly scarce, making this a timely opportunity for 180SX owners dealing with vacuum leaks, dirty valves, or failing electronics that cause hesitation and poor drivability. Proper function of this component is essential for smooth daily driving, reliable cold starts, and consistent boost transitions.
At Terra Firma Automotive, we specialize in hard-to-find genuine Nissan parts for the SR20 platform and supply this authentic IACV-AAC as the definitive fix for S13 180SX owners who refuse to compromise on reliability. Whether you're refreshing a high-mileage car or fine-tuning a performance build, this valve ensures your engine idles cleanly and responds instantly when you need it most. Secure one of the remaining units today and experience the difference that genuine Nissan engineering makes in your SR20-powered 180SX.
- Genuine Nissan OEM Idle Air Control Valve Assembly (IACV-AAC)
- Part Numbers: 23781-50F05 / B3781-50F05
- Relaces USDM 240SX unit as Well
- Direct fit for Nissan 180SX S13 SR20DET
- Restores stable idle, eliminates stalling at boost, and improves cold starts
- Brand-new, never-installed factory unit
- Precise ECU-controlled airflow management
- Critical for smooth throttle response and drivability
- Ideal for stock to highly modified SR20 builds
- Addresses common idle issues caused by wear or contamination
- Essential maintenance item for reliable SR20 performance
- Trusted OEM quality from Nissan
- Supports overall engine efficiency and boost transitions
- Perfect upgrade for performance 180SX owners
- Limited availability — secure yours now
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