Preliminary Checks

Most driveability problems in the throttle body fuel injector system result from faulty wiring and/or leaking vacuum hoses and hose connections. To avoid unnecessary component testing, visual check should be performed before beginning trouble shooting procedures to help spot these common faults. Preliminary visual check should include:

• Air ducts at air cleaner and throttle body.
• All electrical connections at components.

Check vacuum lines for tight leak-free connections in these areas:

• Throttle body (2 front, 2 rear).
• Purge solenoid (bracket above right front wheelwell).
• Charcoal canister.
• PCV valve to intake manifold vacuum port.
• EGR backpressure transducer.
• MAP sensor.

Ensure that following electrical connectors are properly attached:

• Two 25-way (Black and White) logic module connectors.
• 3-way MAP sensor connector.
• 12-way and 10-way power module connectors.
• 2-way purge solenoid connector.
• 2-way speed sensor connector.
• 2-way throttle body temperature sensor connector.
• 6-way radiator fan relay connector.
• 4-way AIS motor connector.
• 3-way TPS connector.
• 4-way A/C WOT cut-out relay.
• Ground eyelet on left cylinder head.
• 2-way fuel injector connector.
• 1-way oxygen sensor connector.
• 2-way coolant temperature sensor connector.
• 3-way distributor connector.