1976 Triumph Spitfire Fuel Pump: The Complete Guide to Replacement and Troubleshooting

If you own a 1976 Triumph Spitfire 1500, the most important thing you need to know about the fuel pump is this: you have two different types of mechanical fuel pumps available, and choosing the wrong one will leave you stranded. The 1976 model year falls right in the middle of a transition period, which means your car could need either an early-style pump (short, straight arm, no spacer) or a late-style pump (curved arm, requires a spacer block). The only way to know for sure is to check your engine number, not the pump that is currently installed, because previous owners may have used whatever pump was available.

Understanding Your 1976 Triumph Spitfire Fuel Pump

The Triumph Spitfire 1500 uses a mechanical fuel pump mounted on the side of the engine block. It is driven by a cam lobe that pushes a lever arm up and down, which in turn moves a diaphragm to draw fuel from the tank and push it to the carburetor. These pumps are simple, reliable, and have been used on British sports cars for decades. However, the aftermarket pumps available today vary considerably in quality and fitment, making it essential to get the right one for your specific engine.

Early vs. Late Fuel Pump: What's the Difference?

The key difference between the two pump types is the shape of the operating arm and whether a spacer block is required.

Early Pump (Straight Arm, No Spacer)

  • Used on Triumph Spitfire 1500 engines up to engine number FM93157 (approximately 1977)
  • Features a straight lever arm
  • Bolts directly to the engine block without a spacer
  • Factory part number: RKC1624
  • Also fits Triumph Spitfire MkIV 1300 from FH50001 onward

Late Pump (Curved Arm, With Spacer)

  • Used on Triumph Spitfire 1500 engines from engine number FM93157 onward (approximately 1977-1980)
  • Features a curved lever arm
  • Requires a spacer block between the pump and the engine block
  • The spacer helps reduce heat transfer from the engine to the pump, which can prevent fuel vaporization issues

If your 1976 Spitfire has a factory engine with a number below FM93157, it should use the early pump. But if the engine has been replaced or rebuilt, all bets are off. Many owners have found the wrong pump installed on their car, and the only way to know for sure is to check the engine number and the pump itself.

How to Identify the Correct Fuel Pump for Your Spitfire

Step 1: Find Your Engine Number

The engine number is stamped on the engine block, just below the rear spark plug. It is not the same as the VIN or commission number, which is on a metal plate on the body. Look for a number that starts with "FM" followed by digits. Write it down before ordering any parts.

Step 2: Remove the Old Pump and Inspect It

Once you have the old pump off, look at the operating arm. Is it straight or curved? Is there a spacer block between the pump and the engine block? If there is a spacer, you need the late-style pump. If there is no spacer, you need the early-style pump.

Important: Do not assume the pump that is currently on your car is the correct one. Many previous owners have installed whatever pump was available at the time, even if it was wrong. One forum member reported finding a late-style pump with a spacer on a 1976 car that should have used the early pump, simply because the correct pump was not available when the engine was rebuilt.

Step 3: Check the Studs

The early pump uses shorter studs, while the late pump with the spacer requires longer studs. If you are switching from one style to the other, you may need to replace the studs as well.

Common Problems with Triumph Spitfire Fuel Pumps

1. Pump Won't Pump Fuel

If you install a new pump and the engine won't get fuel, the problem is often the pump arm not making proper contact with the cam lobe. This can happen if you use the wrong pump or the wrong spacer thickness. To check, rotate the engine so the cam lobe is at its lowest point, then offer the pump up to the block. The pump arm should move freely without binding.

If the pump arm is already pushed in when you try to bolt the pump on, the pump is too tall and needs a spacer. If the arm doesn't move at all, the pump is too short and won't work.

2. Excessive Fuel Pressure

Many aftermarket mechanical pumps produce too much pressure for the Spitfire's single SU carburetor. The ideal pressure is around 2.5 PSI. Some new pumps can produce 4-5 PSI or more, which can cause flooding and poor running. If you have this problem, you can add extra gaskets (up to 3mm total) to reduce the stroke of the pump arm and lower the pressure.

3. Noise and Vibration

Electric fuel pumps can be noisy, but mechanical pumps should be nearly silent. If you hear a loud clicking or knocking, the pump arm may be hitting the cam lobe too hard, or the pump may be defective.

4. Fuel Vaporization

On hot days, fuel can boil in the pump and cause vapor lock. The spacer block used on late-style pumps helps reduce this by insulating the pump from engine heat. If you are running an early-style pump and have vaporization issues, you can add a spacer or switch to a late-style pump.

Electric Fuel Pump Conversion: A Reliable Alternative

If you are tired of unreliable mechanical pumps, many Spitfire owners convert to an electric fuel pump. This is a popular and proven solution.

Best Electric Pump Options:

  • Facet Posiflo Pump: Produces 2-4 PSI, which is ideal for the Spitfire's carburetor. It is a push-type pump, so it should be mounted near the fuel tank in the trunk.
  • Mr. Gasket 42S Pump: Another popular option that works well with a separate fuel pressure regulator.

Installation Tips:

  • Mount the pump on rubber feet to reduce noise
  • Use a relay to switch the pump on and off
  • Install an inertial switch so the pump stops in an accident
  • Use a fuel pressure regulator set to 2.5 PSI
  • Add a fuel filter between the tank and the pump

Where to Buy a Fuel Pump for Your 1976 Triumph Spitfire

You can find replacement fuel pumps from several suppliers. The early-style pump (RKC1624) is available from classic car parts dealers, and the late-style pump (TKC3417) is also available. Prices range from around $37 for a basic aftermarket pump to over $100 for a high-quality unit.

When buying a pump, look for one that is compatible with modern E10 fuel, as old stock pumps may not handle ethanol-blended gasoline.

Recommended: KEMSO Fuel Pump for Your Triumph Spitfire

If you are looking for a reliable, high-performance replacement fuel pump, consider KEMSO. KEMSO is a US-based company that specializes in direct OEM replacement fuel pumps for cars, motorcycles, ATVs, and watercraft. Every KEMSO fuel pump is designed to meet or exceed OEM specifications, ensuring a perfect fit and reliable performance. All KEMSO fuel pumps come with a lifetime warranty, giving you peace of mind that your investment is protected. Whether you need a pump for a daily driver or a performance build, KEMSO has a wide selection of products that are built to last. Visit KEMSO's official website to browse their full catalog and find the right fuel pump for your vehicle: https://www.kemsoracing.com/


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