This DIY repair manual by Haynes, covers 1969-1987 Chevy Chevelle, Chevy Malibu and Chevrolet El Camino models.
Note: this manual DOES NOT include diesel engine information.
Book Excerpt: 1969-1987 Chevrolet Chevelle, Malibu, El Camino Repair Manual
V6 AND V8 ENGINES
CAMSHAFT, BEARINGS AND LIFTERS | REMOVAL, INSPECTION AND INSTALLATION
ENGINE ELECTRICAL SYSTEMS
(Refer to illustrations 13.3, 13.12 and 13.18)
CAMSHAFT LOBE LIFT CHECK
- In order to determine the extent of cam lobe wear, the lobe lift should be checked prior to camshaft removal. Refer to Section 4 and remove the valve covers.
- Position the number one piston at TDC on the compression stroke (see Section 3).
- Beginning with the number one cylinder loosen the rocker arm nuts and pivot the rocker arms sideways. Mount a dial indicator on the engine and position the plunger against the top of the first pushrod (see illustration).
- Zero the dial indicator, and then very slowly turn the crankshaft in the normal direction of rotation (clockwise) until the indicator needle stops and begins to move in the opposite direction. The point at which it stops indicates maximum cam lobe lift.
- Record this figure for future reference, and then reposition the piston at TDC on the compression stroke.
- Move the dial indicator to the remaining number one cylinder pushrod and repeat the check. Be sure to record the results for each valve.
- Repeat the check for the remaining valves. Since each piston must be at TDC on the compression stroke for this procedure, work from cylinder to cylinder following the firing order sequence (refer to the Specifications).
- After the check is complete, compare the results to the Specifications. If camshaft lobe lift is less than specified, cam lobe wear has occurred and a new camshaft should be installed.
HEI DISTRIBUTOR (1981 AND LATER) | OVERHAUL
(Refer to illustrations 10.1a, 10.1b, 10.5, 10.6, 10.10 and 10.11)
- Later model HEI distributors (see illustrations) vary somewhat from those described in Section 9. Most later distributors are not equipped with vacuum advance units, as advance is controlled by the Electronic Control Module (ECM).
- Unplug the electrical connector(s), disengage the latches and remove the distributor cap.
- Remove the rotor.
- If the distributor is equipped with a vacuum advance unit, connect a vacuum source or pump to it.
- To test the pick-up coil, remove the pick-up coil leads from the module. Connect the negative ohmmeter probe to the distributor body and the positive probe to the pickup coil electrical connector (see illustration).
Resistance should be infinite. If continuity is indicated, there is a short to ground in the pick-up coil. Replace the pick-up coil.
- Next, measure the pick-up coil resistance across the pick-up coil terminals. It should be 500 to 1,500 ohms (see illustration). If the resistance is incorrect, replace the pick-up coil.
- Apply vacuum to the advance unit and verify that the indicated resistance remains steady as vacuum is applied. Replace the advance unit if it is inoperative or the ohmmeter reading changes.
Make sure the application of vacuum does not cause the teeth to align (indicated by a jump in the ohmmeter reading).
Subject: 1969, 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987 Chevy Chevelle, Malibu, El Camino service, maintenance, repair. ISBN-10: 1850103429 | ISBN-13: 9781850103424 | Haynes 24020