POOR ENG. PERF.,ROUGH IDLE,B/F CAMSHAFT FAULT

VEHICLES AFFECTED: 1982-84 Devilles, Broughams, Eldorados and Sevilles Equipped With HT4100 Engine

Listed below is a suggested HT4100 engine camshaft replacement procedure. This procedure was developed by combining several sections of the Service Information Manual. When performing this procedure, all torque specifications, and sequences and procedures as well as all Cautions and Notices must be followed as listed in the appropriate Service Information Manual.

REMOVAL

1. Open hood, cover fenders and disconnect negative battery cable.

2. Remove air cleaner.

3. Drain cooling system.

4. Remove cross brace bolts and loosen nuts and swing braces out of the way (Devilles and Broughams only).

5. Disconnect the power steering reservoir from the fan shroud.

6. Disconnect vapor hose from the fan shroud (Devilles and Broughams only).

7. Remove the lower splash sheild (Eldorados and Sevilles only).

8. Remove radiator.

9. Remove fan shroud and fan assemblies as a unit.

10. Do not remove upper portion of fan shroud from lower portion (Devilles and Broughams only).

11. Discharge the refrigeration system and remove the A/C condenser (Eldorados and Sevilles only).

12. Loosen generator, AIR pump, vacuum pump and A/C compressor mounting bolts and remove the drive belts.

13. Remove A/C compressor without removing hoses and move aside.

14. Remove generator mounting brackets and generator.

15. Remove water pump, crankshaft, and power steering pulleys.

16. Remove crankshaft hub.

17. Remove A/C bracket at water pump.

18. Remove front cover with the water pump and hoses attached.

19. Remove timing chain and sprockets.

20. Disconnect electrical connections and position wiring harness aside.

21. Disconnect heater hose at rear of intake manifold.

22. Disconnect fuel lines from throttle body.

23. Remove the distributor with cap and wires attached.

24. Remove accelerator linakge.

25. Disconnect the AIR management valve from the right exhaust manifold.

26. Remove the rocker arm covers.

27. Remove rocker arm supports and push rods (with rocker arms intact with support.

28. Disconnect vacuum hoses.

29. Remove intake manifold.

30. Remove valve lifters.

31. Remove camshaft.

32. Clean gaskets and RTV from all sealing surfaces.

INSTALLATION

1. Prelube and install camshaft.

2. Prelube and install lifters.

3. Install intake manifold.

4. Install timing chain and sprocket.

5. Install distributor with cap removed.

6. Install distributor cap and connect spark plug wires.

7. Install push rods and rocker arm supports.

8. Install rocker arm covers.

9. Connect fuel lines to throttle body.

10. Install accelerator linkage and adjust TV cable.

11. Connect vacuum hoses.

12. Connect heater hose at rear of intake manifold.

13. Install front cover.

14. Install crankshaft hub.

15. Install water pump, crankshaft and power steering pump pulleys.

lb. Install AIR management valve.

17. Position generator and support bracket onto engine; do not tighten bolts.

18. Install A/C compressor bracket at water pump; do not tighten bolts.

19. Install A/C compressor at brackets; do not tighten bolts.

20. Connect electrical connectors.

21. Install fan shroud and fan as on unit.

22. Tighten drive belts and tighten all accessory drive brackets bolts to specified torque.

23. Install the A/C condenser and charge the refrigeration system (Eldorados and Sevilles only).

24. Install power steering reservoir to fan shroud.

25. Connect vapor hose to the fan shroud (Devilles and Broughams only).

26. Install radiator.

27. Install the lower splash shield (Eldorados and Sevilles only).

28. Install cross braces (Devilles and Broughams only).

29. Connect negative battery cable.

30. Refill cooling system and check for leaks.

31. Install air cleaner.

32. Set ignition timing.

33. Change oil and filter.

34. Remove fender covers; close hood.

Use most applicable labour operation from Canadian Labour Time Guide and Claim.

7.7 hours (Eldorados and Sevilles) 7.2 hours (Devilles and Broughams).

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.