Injector Leak and Spray Pattern Test

NOTE: Before attempting this test, make sure that the fuel system pressure is to specifications. If incorrect fuel pressure is suspected, perform FUEL SYSTEM PRESSURE TEST first.

1. Remove electrical connector from cold start injector.
2. Disconnect the cold start injector from the intake manifold.

Bridging System Relay:

3. Turn ignition OFF.
4. To start fuel pumps, remove the [1][2]system relay (located in center console behind ash tray) and seat belt reminder relay.
5. Connect a lead between terminals 30 and 87/2 and between 30 and 85 on relay base. The fuel pumps should start operating. Check by listening to the pumps. Fuel tank pump can be heard by removing the tank cap. If fuel pumps do not run, see FUEL PUMPS.

Bridging Suppressor Relay:

6. Disconnect suppressor relay located in front of coolant expansion tank.
7. Bridge terminals 3 and 4 of relay base.
8. Check for the one terminal with current at cold start injector connector.
9. Connect a test lead between that terminal and its connection at the injector.
10. Connect a lead between ground and the other terminal at the injector. Injector will now start operating.
11. Use a fuel resistant clear container to catch the fuel.

Spray Pattern Test:

12. Check the spray pattern of the injector.
A poor spray pattern can cause the following problems:

^ Hard starting and stalling when cold.
^ Restart problems after short trips.

If a poor spray pattern is observed, use an industry approved fuel injector cleaning system and perform cleaning process as instructed by cleaner manufacturer. When done, recheck spray pattern.
If fuel injector pattern is very poor, replace and retest with new cold start injector.
13. Use a fuel resistant measuring cup and meter the volume of fuel injected over a one minute period.

Volume: approx. 160 cc/min at correct system pressure of 43 psi (300 kPa)

If reading is different, replace and retest with new cold start injector.
14. Disconnect injector jumper wire to ground.
15. Clean tip of injector immediately and check for injector leakage.

Leakage: less than two drops per minute at tip

If leakage exceeds two drops per minute, replace and retest with new injector.
16. Disconnect all jumper wires, reinstall all relays and the cold start injector (use new gasket if needed).