Fuel injection pump repair is crucial in increasing diesel engines’ longevity and protecting a vehicle’s drivability and regulated emissions. The fuel injection pump’s job is twofold:
1) Forcing fuel from its tank and into the injectors, and
2) Creating adequate pressure so that injectors function properly under correct operating conditions
Deficient fuel injection pumps can lead to engines running lean, leading to hard starting, poor idle quality, and the engine hesitating when accelerating. So how do you diagnose the need for fuel injection pump repair?
 Examining Voltage Supply & Electrical Connections – Blown fuses, open relays, loose wiring, or low battery voltage can reduce the pump’s motor speed.
 Replacing Fuel Filters– One of the most common problems is a clogged fuel filter, so be sure the change the filter based on manufacturer recommendations.
 Measuring Static Output Pressure – Determined with a gauge attached to the fuel rail
 Measuring Fuel Delivery – Determined by detaching the supply line and measuring the volume of fuel delivered.
 Examining Pump’s Check Valve – If this has failed, then the pump will not maintain residual pressure after the ignition is switched off.
So once you have determined whether fuel injection pump repair or replacement is necessary, it is important to determine what brand of fuel injection pump you require. Some of the top manufacturersand their short histories include (in no specific order):
 Bosch – Founded in 1886, this is one of the world’s largest privately-held companies. Robert Bosch GmbH is almost entirely owned by a charitable foundation.
 FP Diesel – Having blossomed from Federal Mogul’s 1997 acquisition of Fel-Pro, FP is now a global brand consisting of CAT, Cummins, Detroit Diesel, John Deere, and Navistar applications.
 Stanadyne – Dating as far back as 1876 with the Hartford Machine Screw Company, Stanadyne offers a variety of pump and injector-related products and additives.
 ProDiesel – Founded in 1959, ProDiesel offers Cummins, Detroit Diesel, Navistar, and CAT applications (among others).
 Delphi – Formed in 1994, Delphi offers a number of injection-related products for light, medium, and heavy duty fuel systems.
 Denso – Founded in 1949 after splitting from Toyota Motor Corporation, Denso ranks as one of the top auto parts suppliers in the world.
Each manufacturer varies in pricing, so doing your research is definitely important in determining your most cost-effective option. Once you have purchased your ideal fuel injection pump and are preparing to outfit your engine, here are a few ideas to keep in mind:
1) Old v. New: On newer vehicles, fuel pumps are usually installed in the fuel tank, whereas older vehicles’ fuel pumps are located on the frame between the tank and engine.
2) Internal Inspection: The inside of fuel tanks should always be inspected and cleaned to protect your new pump against future failure.
3) Disconnection: For internal fuel pump replacements, be sure to disconnect the battery and drain the tank to avoid sparks.
4) New & Improved: Always use new filter screens and O-rings or gaskets for sealing collars. Also replace any connecting pieces if erosion, flaking, or cracking has occurred.
5) No Dry-Runs!:Do NOTtest-run a pump in dry condition for risk of damage.
Fuel injector pump repair can be a tedious task that must be approached with care to avoid ruining replacements. If done correctly, this can be the key to getting your engine back up and running quickly. Keep an eye out for our next article pertaining to the repair and replacement of your diesel injectors.
For further information or help pertaining to fuel pumps and injectors, please contact M&D Distributors at (800) 392-5517, or via our website at http://www.mddistributors.com.