This procedure addresses an anachronism: the 1966 Corvette 327ci V8 uses a mechanical carburetor and does not have a throttle position sensor. This guide documents the non-applicability and suggests likely misdiagnoses.

Warnings

Preparation

1. Verify the year and engine configuration of your vehicle - confirm it is actually a 1966 Corvette with original or period-correct carburetor setup
2. If the engine has been modified with aftermarket electronic fuel injection (such as a Holley, FAST, or Edelbrock EFI conversion), consult the aftermarket system's installation manual for TPS service procedures

Procedure

1. 1

   Verify carburetor presence
   Open the hood and visually inspect the top of the intake manifold. The 1966 327ci V8 will have a large carburetor assembly with mechanical linkage rods connecting to the throttle shaft. There will be no electronic sensors mounted to the throttle body or carburetor, as TPS technology did not exist in production vehicles in 1966.
2. 2

   Check for aftermarket EFI conversion
   If the carburetor has been replaced with a throttle body injection system, identify the manufacturer (look for Holley, Edelbrock, FAST XFI, or similar branding on the throttle body). The TPS on these systems is specific to the aftermarket kit and replacement procedures vary by manufacturer.
3. 3

   Inspect throttle linkage if carburetor-equipped
   With the engine off, manually operate the throttle linkage at the carburetor. Check for binding, worn bushings, or disconnected return springs. The throttle shaft should move smoothly from idle to wide-open throttle and return crisply. Worn throttle shafts in the carburetor body are a common issue on carbureted vehicles and may cause symptoms similar to a faulty TPS on modern vehicles.
4. 4

   Test accelerator pump function
   Remove the air cleaner assembly. With the engine off, look down into the carburetor venturi while manually actuating the throttle linkage. You should see a strong stream of fuel squirt from the accelerator pump nozzle. Weak or absent fuel delivery indicates accelerator pump diaphragm failure, which causes hesitation that mimics TPS issues on fuel-injected engines.
5. 5

   Check vacuum advance operation
   Locate the vacuum advance canister on the side of the distributor. With the engine idling, disconnect the vacuum line from the advance canister and plug the line. If the distributor uses a manifold (full-time) vacuum source, idle speed will drop and timing will retard; if it uses a ported vacuum source, there should be little change at idle since no vacuum is present at the port at idle. Reconnect the line and verify timing advances with throttle application. Faulty vacuum advance causes drivability problems often attributed to sensor issues on modern vehicles.

Reassembly

1. If aftermarket EFI is confirmed, refer to the specific manufacturer's service documentation for TPS replacement procedures and calibration requirements

Verification

• Confirm the vehicle's actual fuel delivery system matches the model year specification (carburetor for 1966)
• If diagnosing poor throttle response, test carburetor accelerator pump, check for vacuum leaks, verify ignition timing, and inspect throttle linkage for wear

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