C 2500 3/4 Ton Pickup 2WD L6-250 4.1L VIN D 2-bbl (1984)
Throttle Position Sensor: Service and Repair
To replace Throttle Position Sensor it is necessary to remove the air horn assembly from the carburetor.
1.
Remove or disconnect electrical connectors from M/C solenoid and TPS assembly.
2.
Remove hose or hoses from choke pull off(s) on air horn assembly.
3.
Remove choke pull off(s) and idle speed solenoid bracket attaching screws from air horn. Rotate choke pull off and bracket assembly to disengage
choke pull off break link (T-Pin) from slot in choke pull off lever and air valve rod from slot in air valve lever.
4.
Remove secondary choke pull off bracket and attaching screws if equipped. Rotate bracket to remove choke pull off link from choke pull off lever
slot. Remove clip from hole in accelerator pump rod.
CAUTION:
Do not remove pump lever retaining screw. Pump lever and washer must not be removed from air horn assembly.
5.
If necessary to remove air valve rod from choke pull off, remove and disregard retaining clip from end of air valve. New retaining clip must be
used when reassembling. Plastic bushing used on rod may be reused.
6.
Remove and disregard retaining clip from intermediate choke rod at choke lever. Use a new retaining clip upon reassembly. Remove choke rod
and plastic bushing from choke lever. Plastic bushing may be reused.
7.
If equipped, remove hot idle compensator valve screws. Remove valve and seal from air horn. Valve removal is necessary to gain access to short
air horn-to-bowl attaching screw.
8.
Remove 3 mixture control solenoid screws and remove mixture control solenoid itself with light twisting motion. Remove solenoid gasket, plunger
seal and plunger seal retainer. Retain spacer for use during reassembly.
9.
Remove air horn-to-float bowl screws and lock washers.
10. Remove vent and screen assembly.
11. Rotate fast idle cam to full "UP" (12 o'clock) position.
12. Remove air horn assembly by tilting to disengage fast idle cam rod from slot in fast idle cam and pump rod from hole in pump lever.
13. Disconnect fast idle cam from choke lever by aligning tang on rod with slot in lever. Remove from air horn assembly.
14. Remove TPS plunger by pushing through seal in air horn. Remove seal retainer and seal. Remove accelerator pump plunger seal from air horn.
CAUTION:
To prevent damage to sealing surface use only your fingers to remove plunger. To prevent damage to air horn, use care in removing plunger seal retainer
and plunger stem seal retainer. Disregard seals and retainers and replace with new ones upon reassembly.
15. It is not necessary to remove choke valve and shaft unless they are bent or damaged. Choke valve screws are staked in placed, and staking must be
removed before screws can be removed.
CAUTION:
Do not remove plug covering idle air bleed screw during routine service. This adjustment is factory pre-set and no attempt should be made to change
this adjustment, unless air horn or float bowl is replaced.
16. Remove air horn gasket, pump plunger and pump spring from pump well.
17. Remove TPS sensor by pushing up on bottom of electrical connector and remove from float bowl.
18. Reverse procedure to install new TPS sensor.
