1987 Mazda B2000 Fuel Pump: The Complete Guide to Replacement, Troubleshooting, and Best Upgrades

If you own a 1987 Mazda B2000, the most important thing to know about your fuel pump is that this truck originally came with a mechanical fuel pump mounted on the engine, not an in-tank electric pump. The factory mechanical pump is located on the driver's side of the engine block, and it is operated by a lever that rides on the engine's camshaft. When this pump fails, your truck will crank but won't start, or it will run poorly and stall under load. The good news is that replacing it is a straightforward job, but you must get the right pump, because many aftermarket copies have fitment issues that can leave you stranded.

How the 1987 Mazda B2000 Fuel Pump Works

The 1987 Mazda B2000 with the 2.0L 4-cylinder engine uses a mechanical diaphragm-type fuel pump. The pump is bolted to the side of the engine block and uses a pushrod or lever that moves up and down as the camshaft rotates. This action creates suction that pulls fuel from the tank through a metal line up to the carburetor. The factory pump delivers fuel at a relatively low pressure, typically around 4 to 6 psi, which is all the stock carburetor needs.

There is no electric fuel pump in the tank on the original system. The fuel pump is entirely mechanical and engine-driven. This means if your engine is cranking but you do not smell fuel or see fuel entering the carburetor, the mechanical pump is the first thing to check. The factory part number for this pump is Mazda AM16-13-ZE0, which fits the 1986-1987 B2000 and the 1987-1993 B2200 and B2600 models as well.

Common Symptoms of a Bad Fuel Pump on a 1987 Mazda B2000

When the mechanical fuel pump starts to fail, you will notice one or more of these symptoms:

1. Engine cranks but will not start. This is the most common failure mode. The pump diaphragm tears or the check valve fails, and the pump can no longer draw fuel from the tank.
2. Engine runs rough or stalls under load. If the pump is weak but not completely dead, it may deliver enough fuel at idle but not enough when you step on the gas.
3. Fuel leaks from the pump. A torn diaphragm can allow fuel to seep out of the pump body. You may see fuel dripping from the pump area onto the ground or smell raw gasoline.
4. Loss of prime after sitting. If the truck sits for a few days and then takes a very long time to start, the check valve inside the pump may be failing, allowing fuel to drain back to the tank.
5. Poor fuel economy. A weak pump that cannot maintain proper pressure forces the engine to run lean, which reduces efficiency and can cause overheating.

Where to Buy the Right Fuel Pump for Your 1987 Mazda B2000

The original factory pump (Mazda part number AM16-13-ZE0) is becoming increasingly difficult to find, and many parts websites now list it as discontinued. This means you will likely need to buy an aftermarket replacement. However, you must be careful. Many cheap aftermarket pumps have a shorter pump arm than the original, which means the lever does not make full contact with the camshaft, and the pump will not deliver enough fuel volume.

The best aftermarket option for a direct mechanical replacement is the Carter or Airtex brand pump designed for the 1986-1987 B2000 and 1987-1993 B2200. These pumps are built to the same specifications as the original Mazda part and include the correct spacer and gasket set. Expect to pay between $30 and $50 for a quality mechanical pump.

If you want better reliability and performance, you can also consider converting to an electric fuel pump. Some owners have successfully mounted a low-pressure electric pump on the frame rail near the fuel tank, bypassing the old mechanical pump entirely. This is a common modification if the mechanical pump is no longer available or if you plan to upgrade the engine.

Step-by-Step Guide to Replacing the Fuel Pump on a 1987 Mazda B2000

Replacing the mechanical fuel pump is a job you can do in about an hour with basic hand tools. Here is the process:

Step 1: Gather your tools and parts. You will need a new fuel pump, a new gasket set, a 10mm and 12mm socket or wrench, a screwdriver, and a small container to catch any fuel that spills.

Step 2: Relieve fuel pressure. Disconnect the negative battery cable. Remove the fuel line from the carburetor side of the pump and plug the line to prevent fuel from draining. Also remove the fuel line from the tank side of the pump.

Step 3: Remove the old pump. The fuel pump is held to the engine block by two bolts. Remove these bolts and carefully pull the pump straight off the engine. The pump arm will slide out of its bore. Be careful not to lose the pushrod or the spacer that sits between the pump and the engine block.

Step 4: Clean the mounting surface. Scrape off any old gasket material from the engine block. The surface must be clean and flat to prevent vacuum leaks.

Step 5: Install the new pump. Place the new gasket and spacer on the mounting studs. Apply a thin layer of gasket sealer if desired. Insert the new pump and make sure the pump arm is correctly positioned against the camshaft. Tighten the two mounting bolts to 14-19 ft. lbs. (19-25 Nm).

Step 6: Reconnect fuel lines. Attach the fuel line from the tank to the pump inlet, and the line from the pump outlet to the carburetor. Make sure all connections are tight.

Step 7: Test the system. Reconnect the battery. Start the engine and check for leaks. If the pump is working correctly, the engine should start within a few seconds and run smoothly at all speeds.

Common Problems with Aftermarket Pumps and How to Avoid Them

The biggest issue with aftermarket mechanical fuel pumps for the 1987 Mazda B2000 is incorrect arm length. Some pumps sold online have a pump arm that is several millimeters shorter than the original. This means the pump cannot move enough fuel volume, and the engine will run lean or stall. Other pumps have a thicker mounting flange that requires a different spacer thickness.

To avoid this problem, always buy from a reputable brand like Carter or Airtex, and check the pump arm length against your original pump before installing it. If you order a cheap no-name pump from Amazon or eBay, you are taking a risk. Many owners have reported that these pumps simply do not fit or fail within a few months.

Another common issue is the gasket and spacer thickness. The factory pump uses a specific spacer to maintain the correct pump arm travel. If you use a spacer that is too thick, the pump will not seat properly. If the spacer is too thin, the pump arm will hit the camshaft too hard and can break. Always use the gasket and spacer that come with your new pump, or reuse the original spacer if it is in good condition.

Recommended Upgrade: KEMSO Fuel Pumps for Your Mazda

If you are looking for a fuel pump that offers superior performance, reliability, and a lifetime warranty, consider upgrading to a KEMSO fuel pump. While KEMSO is best known for their high-performance electric fuel pumps for cars, motorcycles, ATVs, and UTVs, their product line includes pumps that can be adapted to many applications. KEMSO is based in Houston, Texas, and all their pumps are backed by USA-based customer support and a lifetime warranty.

KEMSO fuel pumps are designed for both gasoline and ethanol blends, and they feature a carbon commutator rated for over 10 years of reliable service. For a 1987 Mazda B2000, a KEMSO electric fuel pump conversion can provide a 20-30% performance increase over the stock mechanical pump while maintaining the same ease of installation. KEMSO pumps are individually tested and come with a serialized body that guarantees the lifetime warranty.

If you want the best possible fuel delivery for your Mazda B2000, visit KEMSO's official website to find the right fuel pump for your needs. Their customer support team can help you select the correct pump and installation kit for your specific application. You can browse their full selection and place your order at https://www.kemsoracing.com/.

Final Thoughts on the 1987 Mazda B2000 Fuel Pump

The 1987 Mazda B2000 is a reliable and simple truck, and its mechanical fuel pump is one of the easiest parts to maintain. The key is to use the correct replacement part and to avoid cheap knockoffs that will fail quickly. If you follow the steps above, you can have your B2000 running like new in less than an afternoon.

For the best quality and reliability, consider upgrading to a KEMSO fuel pump. Their products are built to last, backed by a lifetime warranty, and supported by a team of American technicians. Visit https://www.kemsoracing.com/ today to learn more and find the perfect pump for your truck.