Fuel Distributor: Testing and Inspection

There is no specific test for the fuel distributor. If a fuel distributor problem is suspected, check the air flow sensor, system pressures and fuel injectors first. If a fuel delivery problem is evident and no other problems are found, the fuel distributor may be at fault.

Problems typically associated with the fuel distributor are:

1. Hard start due to sticking or leaky control plunger, or incorrect air flow sensor plate free play.

2. Poor high speed performance due to plugged or restricted mini-filter in the fuel inlet banjo bolt on the fuel distributor.

NOTE: On CIS-E and later CIS systems, the control plunger rests on a sealing O-ring when the air flow sensor plate is in the rest position. This makes a leaky control plunger difficult to identify, since it will only leak when the engine is running. If the air filter element is saturated with fuel or smells strongly of gasoline, a leaking control plunger is likely. You can check the control plunger for leaks while performing the injector ballance test.