Idle Speed Control Units are compact electronic modules that keep engine idle stable by adjusting throttle input in response to load and temperature changes. What it does: modulates throttle to hold a target idle RPM, reducing rough idle and stalling. Why you need it: prevents idle drops when A/C, lights, or accessories come on; improves drivability and starting reliability. What makes it better: broad compatibility with most gasoline engines using electronic throttle control, rugged compact enclosure, easy installation, and an adjustable idle range. Key attributes Function: automatic idle regulation that tracks signals and maintains target RPM Compatibility: fits most EFI engines and common aftermarket ECUs; integrates with standard wiring Size: small, compact module designed for tight installs Material: rugged enclosure built to withstand engine bay temperatures Performance: fast response to load changes; stable idle within a narrow RPM band across ambient temps Use scenarios Classic car retrofit to restore smooth idle after electronic throttle upgrades Vehicles with electrical loads or frequent A/C use to prevent idle fluctuation Marine engines or portable generators requiring steady idle under varying loads