Sierra 18-7630 Throttle Position Sensor for 5.7L 350 V-8 EFI Marine Engines

The Sierra 18-7630 is a throttle position sensor built for 5.7L 350 cubic inch V-8 EFI marine engines. Mounted to the throttle body, this sensor tracks the position of the throttle valve and sends a continuous electrical signal to the engine control module so the engine management system can adjust fuel delivery and ignition timing in real time as the throttle is opened and closed. A throttle position sensor that reads out of range or fails intermittently is a common cause of rough idle, hesitation on acceleration, or stored fault codes, making the 18-7630 a straightforward diagnostic and maintenance replacement for boat owners running fuel-injected 5.7L 350 V-8 engines.

This part is engineered to match OEM electrical and mechanical specifications for its application, so it installs in the factory sensor location without modification. It is intended as a direct service replacement rather than a universal or aftermarket-style substitute, keeping the throttle-to-ECM signal path within factory tolerances.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-7630
• Product Type: Throttle Position Sensor
• UPC: 030999977106
• Weight: 0.05 pounds
• Application: 5.7L 350 cubic inch V-8 EFI marine engines

Fitment

• 5.7L EFI, 5.7L 350 V-8, model years 1995-1997, serial number range F225560 - K999999
• 5.7L EFI (GEN +), 5.7L 350 V-8, model years 1998-2001, serial number range L010035 - M299999
• 5.7L EFI MIE (GEN +), 5.7L 350 V-8, model year 1997, serial number range K040300 - K999999
• 5.7LX Bravo EFI (GEN +), 5.7L 350 V-8, model years 1996-1997, serial number range F800300 - K999999
• 5.7LX EFI, 5.7L 350 V-8, model years 1995-1997, serial number range F225560 - K999999

Frequently Asked Questions

What does the Sierra 18-7630 throttle position sensor do? It mounts to the throttle body of a 5.7L 350 V-8 EFI marine engine and sends a continuous signal to the engine control module reporting throttle valve position, which the ECM uses to adjust fuel delivery and timing as the throttle opens and closes.

Which engines does the 18-7630 fit? The Sierra 18-7630 fits 5.7L 350 cubic inch V-8 EFI marine engines, including the 5.7L EFI, 5.7L EFI (GEN +), 5.7L EFI MIE (GEN +), 5.7LX Bravo EFI (GEN +), and 5.7LX EFI engine families within their listed serial number ranges.

How much does the 18-7630 weigh? The Sierra 18-7630 throttle position sensor weighs 0.05 pounds.

Is the 18-7630 a direct OEM-fit replacement? Yes, the Sierra 18-7630 is built to match OEM mechanical and electrical specifications so it installs in the factory throttle position sensor location on covered 5.7L 350 V-8 EFI engines without modification.

What year range does the 18-7630 cover? Coverage depends on the specific engine family: 1995-1997 for the 5.7L EFI and 5.7LX EFI, 1996-1997 for the 5.7LX Bravo EFI (GEN +), 1997 for the 5.7L EFI MIE (GEN +), and 1998-2001 for the 5.7L EFI (GEN +), each within a specific serial number range.

Why would I need to replace a throttle position sensor? A failing or out-of-range throttle position sensor like the 18-7630 commonly causes rough idle, hesitation on acceleration, or stored engine fault codes on 5.7L 350 V-8 EFI marine engines, since the ECM can no longer accurately track throttle position.

Does the Sierra 18-7630 use its own serial number range to confirm fitment? Yes, each covered engine family has a specific serial number range, for example F225560 - K999999 for the 5.7L EFI and 5.7LX EFI engines, and confirming your engine's serial number against these ranges ensures the 18-7630 is the correct sensor.

What is included with the 18-7630? The Sierra 18-7630 is sold as the throttle position sensor unit itself for installation on the throttle body of a covered 5.7L 350 V-8 EFI marine engine.

Will the 18-7630 fit a Black Scorpion 350 V-8? No, the Black Scorpion 350 V-8 applications listed in Sierra fitment data use different sensor part numbers, so the 18-7630 is not the listed sensor for Black Scorpion engines.

Is the 18-7630 a genuine Sierra part or an aftermarket substitute? The 18-7630 is a Sierra-branded throttle position sensor manufactured to OEM specification for the covered 5.7L 350 V-8 EFI engines, not a generic aftermarket substitute.