Change The Ignition Timing In An F150

You can set the initial base timing on your F-150 truck with a timing light and a few simple steps.

The Ford F-150 distributor ignition operates like that of any vehicle, only some of the newer models have a computer, or power control module that controls the ignition system. Engine speed, readings from the mass airflow sensor, throttle positioning, load and temperature variations all contribute to the timing sequence of ignition firing. However, the base timing timing on the Ford F-150 truck can be set manually. Setting or adjusting the correct ignition timing will improve overall performance and increase fuel economy.


1. Place the shift selector in park if you have an automatic transmission, or neutral if you have a standard transmission. Firmly set the emergency brake, but have an assistant sit in the cab and depress the foot brake, as an added precaution. Open the vehicle hood and look down at the front of the engine where the crankshaft pulley (harmonic balancer) sits. Look for a metal tab over-hanging the crankshaft pulley. Use some carburetor cleaner and a rag to clean the exterior surface of the crankshaft pulley and tab.

2. Tell your assistant to turn the ignition key on and off briefly to rotate the crankshaft in small increments until you see a small notch in the end of the crankshaft pulley. Mark the notch with a piece of white chalk, as well at the edge of the tab pointer. Start the engine and let it run until it reaches normal operating temperature. Shut the engine off and let it cool for a few minutes.

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3. Locate the “sprout connector” wire on its harness. Refer to your owner’s manual for its location. On the F-150 truck, it will be located near the inner fender next to the ignition module. Pull the connector out and set it aside — do not lose it. Locate the number cylinder on your engine by referring to your manual. It will be on the passenger side closest to you as you face the front of the engine. Hook the plug wire clamp from a timing light around the # 1 plug wire.

4. Hook the red, positive clamp lead of the timing light to the red, positive terminal on your battery. Hook the black, negative lead of the timing light to the black, negative lead on your battery. Take a long extension, universal joint, socket and ratchet to loosen the distributor clamp bolt at the bottom of the distributor. Loosen the clamp bolt only enough to allow the distributor to twist with some force.

5. Have your assistant start the engine. Point the timing light down at the crankshaft pulley, and notice how the pulsing light picks up both chalk marks. To set the timing properly to initial 10 degrees BTDC (before top dead center), you must turn the distributor so that the chalk marks align. If you wish any other adjustment, you must turn the distributor clockwise or counterclockwise to advance or retard the timing.

6. Once you have set your timing, shut the engine off. Tighten down the distributor clamp bolt with the socket, universal socket, extension and ratchet wrench. Plug the sprout connector back into its wire jack. Remove the timing light leads.

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