Injector Equal Delivery Test

1. Make a plastic test line for each injector by cutting 4mm clear plastic tubing into 24 inch lengths. Locate a rubber fuel line that will slip over the plastic tubing and cut into 1.5 inch lengths. Slip the rubber hose over the plastic tubing approximately one inch. Mark each test line every 6.5 inches from the end of the rubber hose with a paint dot.
2. Connect a test line to one of the bleed off ports of the injector. Plug off the other bleed off port with a rubber plug. Tie the lines together and suspend them from the hood, using a piece of wire to hang them from. Do not plug off the end of the lines. They must remain open.
3. Start the engine and idle at 750 RPM for 2.5 minutes. Shut off the engine and compare the fuel level in the lines. If the fuel discharged is equal to 1.5 cc, proceed to step 4. If the fuel discharged is not equal to 1.5 cc, replace injectors as required.
4. If the engine still vibrates and the idle speed, compression, injection pump timing, and engine mounts are good, have the injection pump serviced at a Bosch service center.