1. Cable Issues:
* Lubrication: The throttle cable itself might be sticky due to corrosion, dirt, or lack of lubrication. Do NOT use WD-40. It's a temporary fix that can attract more dirt and eventually gum up the cable worse. Use a cable lubricant specifically designed for throttle cables. Apply it sparingly at the cable ends and work it in by gently moving the throttle. You might need to disconnect the cable from the throttle body to fully lubricate it.
* Kinks or Binding: Inspect the entire length of the throttle cable for kinks, bends, or areas where it's rubbing against something. Repair or replace any damaged sections. Ensure the cable is routed correctly and has enough slack – too much tension or too little can cause sticking.
* Cable Adjustment: Incorrect cable adjustment can lead to a sticky throttle. The cable has an adjustment mechanism (usually near the throttle body) that allows you to fine-tune the throttle position. Consult your repair manual for the correct adjustment procedure. Be cautious not to over-adjust.
2. Throttle Body Issues:
* Dirt and Debris: The throttle body itself can accumulate dirt, grime, and carbon deposits that hinder smooth movement of the throttle plate. This requires cleaning. You'll need:
* Throttle Body Cleaner: Specifically designed for this purpose.
* Shop rags or paper towels: Avoid using anything that might leave lint.
* Screwdrivers: To remove the throttle body (possibly). Sometimes you only need to clean it in-place.
* Protective eyewear and gloves: This process can be messy.
* Procedure: Disconnect the battery negative terminal. Then, carefully remove the throttle body (consult a repair manual for specifics). Clean all surfaces thoroughly, paying close attention to the throttle plate and its shaft. Reinstall and reconnect the battery.
* Sticking Throttle Plate: The throttle plate itself might be sticking due to carbon buildup or damage. Cleaning might resolve this, but if the plate is warped or damaged, replacement may be necessary.
* Return Spring: The throttle return spring ensures the throttle closes completely. A weakened or broken spring will prevent the throttle from returning to its idle position, resulting in a sticky or high-idle condition. Inspect and replace if necessary.
3. Vacuum Leaks:
* Check all vacuum lines connected to the throttle body and related components for cracks or leaks. Vacuum leaks can cause erratic idle and potentially contribute to a sticky throttle feeling.
Troubleshooting Steps:
1. Start with the simplest: Try lubricating the cable first.
2. Inspect visually: Carefully examine the cable and throttle body for obvious problems.
3. Clean the throttle body: This is often the most effective solution.
4. Check the return spring: Ensure it's functioning correctly.
5. Inspect vacuum lines: Look for leaks or damage.
Important Considerations:
* Repair Manual: A repair manual for your specific vehicle is invaluable. It will provide detailed diagrams, instructions, and torque specifications.
* Safety First: Disconnect the battery negative terminal before working on any electrical or fuel system components.
* Professional Help: If you're uncomfortable performing these repairs yourself, consult a qualified mechanic. A sticking throttle is a safety hazard that shouldn't be ignored.
Remember to double-check all your work before starting the engine and test the throttle response carefully after each step. If the problem persists after trying these solutions, a more serious issue may be at play, requiring professional diagnosis.
