Camshaft: Service and Repair
1. Disconnect battery ground cable.2. Remove undercover, then drain engine coolant and engine oil.
3. Disconnect exhaust pipe from exhaust manifold.
4. On 1992 models, loosen power steering pump adjusting bolt and pivot bolt, remove belt, remove adjusting bolt, pivot and pump and position pump assembly aside, then remove adjusting bar.
5. On all models, remove air cleaner assembly.
6. Disconnect accelerator cable and throttle cable, if equipped.
7. On models equipped with 4A-FE engine, remove cruise control actuator cable.
8. On all models, disconnect all necessary electrical connectors.
9. Disconnect necessary vacuum lines.
10. On models equipped with 4A-F engine, disconnect fuel hoses from fuel pump.
11. On all models, disconnect radiator hoses from engine.
12. On models equipped with 4A-F engine, disconnect heater hose from cylinder head rear cover, then the water bypass hose and remove water outlet.
13. On models equipped with 4A-FE engine, disconnect heater hoses, then remove water outlet.
14. On all models, remove exhaust manifold upper shield, then the manifold.
15. Remove distributor assembly.
16. Disconnect hoses from water inlet housing and remove housing.
17. On models equipped with 4A-F engine, remove fuel pump and fuel pump insulator.
18. On models equipped with 4A-FE engine, disconnect fuel return hose, then remove fuel supply pipe.
19. Remove cold start injector pipe.
20. Remove EGR vacuum modulator.
21. Remove fuel delivery pipe with fuel injectors as an assembly.
22. On all models, disconnect PCV and water hoses from intake manifold, then remove the manifold.
23. On models equipped with 4A-F engine, loosen water pump pulley, then remove the drive belt.
24. On models equipped with 4A-FE engine, remove water pump pulley, then the drive belt.
25. On all models, remove power steering pump stay if equipped, then the spark plugs.
26. Remove cylinder head cover and gasket.
27. Remove No. 3 and No. 2 timing belt covers.
28. If timing belt is to be replaced, refer to TIMING BELT for procedure. If timing belt is to be reused, proceed as follows:
a. Turn crankshaft pulley and align groove with ``0'' mark on the No. 1 timing belt cover. Ensure all valve lifters on the No. 1 cylinder are loose. If not, turn crankshaft pulley one complete revolution.
b. Place alignment marks on the camshaft timing pulley and belt.
c. Loosen idler pulley bolt, then push idler pulley as far left as possible and temporarily tighten it.
d. Remove timing belt from camshaft timing pulleys. Support timing belt so meshing of crankshaft timing pulley and timing belt does not shift.
e. Remove camshaft timing pulley.
Fig. 1 Measuring Camshaft Thrust Clearance:
29. Measure camshaft thrust clearance, Fig. 1. If clearance is greater than .0043 inch, replace camshaft and/or cylinder head.
30. Loosen No. 1 intake and exhaust bearing cap bolts gradually, then remove bearing caps.
31. Secure the intake camshaft sub-gear to to the main gear, using a suitable 6mm bolt.
Fig. 7 Intake Camshaft Bearing Cap Bolt Removal.:
Fig. 8 Exhaust Camshaft Bearing Cap Bolt Removal.:
Fig. 9 Cylinder Head Bolt Removal Sequence. 4A-F & 4A-FE:
32. Loosen bearing cap bolts gradually in sequence shown in Figs. 7 thru 8, then remove the bearing caps.
33. Remove intake and exhaust camshafts. Do not pry on camshafts or cylinder head.
34. Loosen and remove cylinder head attaching bolts gradually in sequence shown in Fig. 9, Head warpage or cracking could result from removing cylinder head bolts in incorrect order.
35. Remove cylinder head.
Fig. 11 Head Bolt Tightening Sequence. 1990-92 4A-FE:
Fig. 13 Exhaust Camshaft Bearing Cap Bolt Tightening Sequence. 1990-92 4A-FE:
Fig. 14 Intake Camshaft Bearing Cap Bolt Tightening Sequence.:
36. Reverse procedure to install. Torque cylinder head attaching bolts in several passes to 44 ft. lbs in sequence shown, Fig. 11.
37. Apply MP grease to the thrust portion of the camshaft. Engage the intake camshaft gear to the exhaust camshaft gear by matching the assembly installation marks on each gear.
Note: There are also timing marks (for TDC) on each gear as shown in the illustration. Do not use these marks. Roll down the intake camshaft onto the bearing journals while engaging gears with each other.
Note: The above angle allows the No.1 and No.3 cylinder cam lobes of the intake camshaft to push their valve lifters evenly.
38. Turn the exhaust camshaft clockwise, and set it with the knock pin facing upward.
39. Check that the timing marks of the camshaft gears are aligned.
Note: The assembly installation marks are on the upside.
40. Torque bearing cap attaching bolts gradually in three steps in sequence Figs. 13 and 14, to 9 ft. lbs.