How to Change the Fuel Pump on a Mopar 318

The Chrysler Corporation 318 cubic-inch V8 “LA” series engine was the successor to the 273 V8. The 318 has a mechanical fuel pump that mounts on the timing cover. The pump has a spring-loaded arm that rides on an eccentric attached to the camshaft. The eccentric is a round part that is mounted off-center on the camshaft and pushes on the fuel pump arm. There's a fuel filter attached to the outlet line that should also be replaced with the pump.

Park the vehicle on a level, paved surface. Set the parking brake.

Slide a drain pan under the fuel pump. The fuel pump is on the front passenger's side of the engine, attached to the timing cover. Loosen the hose clamp where the rubber fuel tank supply line attaches to the fuel pump. Pull the line off of the fuel pump fitting and immediately plug it with a 3/8-inch bolt.

Use a wrench to remove the carburetor supply line. A small amount of gas will run back out of the line. If you want to replace the fuel filter, which is a good idea, loosen the hose clamps on each end of the filter and remove the rubber lines.

Remove the two bolts that hold the pump onto the timing cover. Pull the pump away from the timing cover. As you are removing the bolts you may notice that something is pushing against the pump. This is the eccentric on the camshaft pushing on the fuel pump arm.

Remove the gasket from the timing cover if it didn't come off with the pump. Scrape any remaining material from the timing cover with a putty knife. Spray some parts cleaner and a shop rag and clean the gasket surface of the timing cover.

Coat the gasket surfaces on the fuel pump and timing cover with gasket sealer. Coat both sides of the gasket with gasket sealer and mount the gasket on the fuel pump. Slide the pump into the timing cover and start the bolts by hand. You may have to exert a little bit of pressure on the pump to hold it in position to line up the bolts because of the arm making contact with the eccentric. Once you have the bolts started, use a ratchet socket to tighten the bolts a little bit at a time, switching back and forth between the bolts until they are tight.

Thread the carburetor supply line into the fuel pump fitting by hand to avoid damaging the threads then tighten the fitting with a wrench. If you're replacing the fuel filter, install it on the rubber lines and tighten the hose clamps. Make sure to filter is pointing in the right direction. It should have an arrow indicating the direction of fuel flow towards the carburetor.

Remove the bolt from the fuel tank supply line and push the line onto the fuel pump fitting. Tighten the hose clamp. Remove the drain pan. Start the engine and check for leaks.