Throttle Body: Service and Repair
REMOVAL1. Disconnect negative battery cable and set aside.
NOTE: When the battery has been disconnected and reconnected, some abnormal drive symptoms may occur while the powertrain control module relearns its adaptive strategy. The vehicle may need to be driven 10 miles or more to relearn the adaptive strategy.
2. Remove PCV closure and aspiration hoses from clean air flex tube.
3. Loosen clean air flex tube retaining clamp at throttle body and disconnect tube.
4. Relieve pressure at the fuel pressure relief valve.
5. Disconnect fuel supply hoses to cold start injector (CSI).
6. Remove idle air control (IAC) solenoid snowshield.
7. Disconnect throttle cable from throttle body.
8. Remove two throttle cable bracket retaining bolts from side of throttle body and remove bracket.
9. Mark location and remove vacuum hoses attached to vacuum tree and EGR valve.
10. Disconnect differential pressure feedback (DPFE) sensor hoses from EGR tube nipples.
11. Loosen EGR tube nut at EGR valve.
12. Remove vapor purge hose from fitting near throttle position sensor.
13. Disconnect electrical connectors to idle air control (IAC), differential pressure feedback (DPFE), cold start injector (CSI) and throttle position sensors.
14. Remove generator brace retaining nuts from generator bracket and throttle body stud.
15. Loosen and remove five throttle body retaining bolts and stud bolt noting their locations.
16. Lift throttle body straight up and remove PCV hose from beneath assembly. Maneuver throttle body away from EGR tube and remove assembly.
17. Cover intake manifold ports to prevent foreign material from entering manifold.
INSTALLATION
1. Clean and inspect sealing surfaces of intake manifold and throttle body.
2. Install guide pins if available in front and rear bolt holes.
3. Place new intake manifold gasket over guide pins.
4. Align bolt holes, lower assembly enough to install PCV hose to tube beneath the throttle body. Align EGR tube nut to EGR valve and lower assembly onto intake manifold. Start EGR tube nut engagement to EGR valve. Install four center retaining bolts and hand tighten. Remove guide pins. Install stud bolt and remaining retaining bolt.
5. Install generator brace to throttle body and generator bracket.
6. Tighten EGR tube nut.
7. Connect DPFE sensor hoses to EGR tube nipples. Check for cracked or deformed condition and replace as necessary.
8. Connect premarked vacuum lines to their original locations. Check for cracked or deformed condition.
9. Connect electrical connectors to TP, DPFE, CSI and IAC sensors.
10. Install vapor purge hose to fitting neat TP sensor.
11. Install throttle cable bracket to side of throttle body.
12. Connect throttle cable and Throttle Valve (TV) cable to throttle body lever.
13. Connect fuel supply tubes to CSI assembly.
14. Install clean air flex tube to throttle body. Connect PCV closure and aspirator hose to their original locations.
15. Connect negative battery terminal.
16. Start engine and check for vacuum, exhaust and fuel leaks.
17. Check engine idle. Adjust as necessary.
18. Install snowshield onto IAC valve.