DTC 25

1. Disconnect fuel hose between pressure regulator and fuel distributor pipe. Fuel line is still under pressure. When disconnecting fuel hose, cover up joint with rag to prevent gasoline from spraying.
2. Connect fuel pressure gauge across pressure regulator and fuel distributor pipe.
3. Start engine and allow to reach normal operating temperature, then idle at 900 RPM.
4. Disconnect VSV harness electrical connector, then apply battery voltage to the VSV. Pressure gauge should read approximately 35 psi.
5. If pressure is not as specified, replace VSV. If pressure is as specified, proceed to step 7.
6. Stop engine and reconnect fuel hose.

Fig. 62 VSV circuit identification.:

Fig. 65 VSV circuit voltage & resistance value chart.:

7. Check voltage and resistance of VSV circuit as shown in Fig. 62 then compare with specifications in chart, Fig. 65
8. If measured voltage or resistance is not as specified in chart, repair or replace faulty wires.