Ensuring your engine’s timing is accurately set is crucial for optimal performance, fuel efficiency, and longevity. Modern vehicles rely on precise timing controlled by the engine control unit (ECU), but sometimes adjustments or checks are necessary, especially after certain repairs or modifications. While dealerships offer timing adjustment services, they can be costly. Fortunately, with the right car scanner, you can accurately set your engine’s timing yourself, saving money and gaining a deeper understanding of your vehicle’s engine management system.
One common scenario where timing adjustment is needed, particularly in older Vortec engines, involves setting the Camshaft Position (CMP) retard. This adjustment ensures the camshaft and crankshaft are properly synchronized, which is vital for efficient combustion and preventing potential engine issues. Traditionally, mechanics might use methods like adjusting the distributor cap, but these are less precise and don’t provide real-time feedback. A car scanner that reads live data, specifically CMP retard, offers a far more accurate and user-friendly approach.
So, what kind of car scanner do you need to set timing, and specifically, CMP retard? The good news is you don’t need to break the bank. While professional-grade scan tools exist, several affordable options can effectively read the necessary live data for timing adjustments.
One popular and budget-friendly solution involves using a Bluetooth OBD2 dongle with a smartphone app. These dongles, often costing under $20, plug into your car’s OBD2 port and communicate wirelessly with your smartphone. Combined with the right app, you can access a wealth of engine data, including CMP retard.
Apps like Torque Pro (for Android) and DashCommand (available on both Android and iOS, though Android is often cited for better customization in this context) are frequently recommended by DIY mechanics. These apps, often costing under $10, allow you to read and display live engine parameters. For specific readings like CMP retard on GM Vortec engines, you may need to add custom PIDs (Parameter IDs) within the app settings. These PIDs are essentially codes that tell the app where to find specific data points within your vehicle’s computer system.
For example, Torque Pro users often utilize a custom PID with the Mode and PID code 221301 to read “Cam Position Retard Offset”. This custom PID, along with other settings like scale factor and units, needs to be entered into the app to correctly interpret and display the CMP retard value in degrees. Online forums and communities dedicated to specific vehicle makes and models are excellent resources for finding these custom PIDs.
Once you have your OBD2 dongle connected and your app configured to read CMP retard, the process of setting the timing typically involves the following steps:
- Warm up your engine: Ensure your engine is at its normal operating temperature.
- Connect your scanner: Plug in your OBD2 dongle and connect it to your smartphone app.
- Locate CMP Retard reading: In your app, find the live data display for CMP Retard (or the custom PID you set up).
- Monitor at idle and 1000 RPM: Observe the CMP Retard value at idle and then slightly increase the engine speed to around 1000 RPM. For Vortec engines, the target range is often between 0° TDC (Top Dead Center) and -2° TDC.
- Adjust distributor (if applicable): On older vehicles with adjustable distributors, you may need to slightly rotate the distributor while monitoring the CMP Retard value on your scanner. Make small adjustments and observe the reading until you achieve the desired range. Note: Many newer vehicles do not have adjustable distributors, and timing adjustments may involve different procedures.
- Re-check and fine-tune: After making adjustments, re-check the CMP Retard value at 1000 RPM and idle to ensure it’s within the specified range. Fine-tune as needed.
While apps like Torque Pro and DashCommand are powerful and affordable, dedicated handheld car scanners are also available that can read live data and are designed specifically for automotive diagnostics. These scanners may offer a more user-friendly interface and more robust features, but they typically come at a higher price point compared to OBD2 dongle and app combinations. Brands like Autel, Launch, and Innova offer scanners in various price ranges that can be used for timing adjustments and other diagnostic tasks.
In conclusion, setting your engine’s timing, including CMP retard, is achievable for DIY mechanics using readily available and affordable car scanners. By utilizing a Bluetooth OBD2 dongle with a smartphone app like Torque Pro or DashCommand, or opting for a dedicated handheld scanner, you can gain the ability to monitor and adjust your engine’s timing for improved performance and efficiency, all without the need for expensive dealership services. Remember to always consult your vehicle’s service manual for specific timing specifications and procedures for your make and model.
