This repair manual covers 1991-1996 Chevy Impala SS, and Caprice and 1991-1996 Buick Roadmaster models. Note: this manual does not include V6 engine information.
Book Excerpt: 1991-1996 Chevy Impala SS, Caprice, Buick Roadmaster Repair Manual ENGINE ELECTRICAL SYSTEMS

IGNITION TIMING - CHECK AND ADJUSTMENT (1993 AND EARLIER MODELS) (Refer to illustration 9.5) NOTE: If the information in this Section differs from the Vehicle Emission Control Information label in the engine compartment of your vehicle, the label should be considered correct.

1. Warm the engine to normal operating temperature. Turn the air conditioning and all accessories off.
2. Place the transmission in Park, apply the parking brake and block the wheels to prevent movement of the vehicle.
3. If the SERVICE ENGINE SOON light is On, don't proceed with the ignition timing check until the problem is solved (see Chapter 6).
4. The Electronic Spark Timing (EST) system must be bypassed prior to checking the ignition timing. Locate the EST bypass connector near the air control valve on top of the right cylinder bank valve cover. Disconnect the EST bypass connector.
5. Locate the timing marks at the front of the engine (they should be visible from above) (see illustration). The crankshaft balancer has a groove in it and a small metal plate with notches and number is attached to the timing cover. Clean the plate with solvent so the numbers are visible.
6. Use chalk or white paint to mark the groove in the balancer and highlight the notch or point on the timing plate at TDC.
7. With the ignition switch off, connect a timing light according to the manufacturer's instructions. Install the inductive pick-up onto the number one cylinder spark plug wire. Make sure the timing light wires are routed away from the drivebelts and fan.
8. Start the engine and allow it to warm up to normal operating temperature. Aim the timing light at the timing scale on the front engine cover. The mark on the crankshaft pulley should align with the TDC mark on the scale. The timing on these models is 0 degrees TDC. If necessary, loosen the distributor hold-down bolt and slowly rotate the distributor until the timing marks align. Tighten the hold-down bolt and recheck the timing.

SUSPENSION AND STEERING SYSTEMS

BALLJOINTS | CHECK AND REPLACEMENT CHECK

1. Inspect the control arm balljoints for looseness whenever either of them is separated from the steering knuckle. See if you can turn the ballstud in its socket with your fingers.
2. If the balljoint is loose, or if the ballstud can be turned, replace the balljoint. You can also check the balljoints with the suspension assembled as follows.
3. Raise the front of the vehicle and support it securely on jackstands placed under the lower control arms. Position the stands as close to each balljoint as possible. Make sure the vehicle is stable. It should not rock on the stands.
LOWER BALLJOINTS (Refer to illustration 8.5)
4. Wipe each balljoint clean and inspect the seal for cuts and tears. If the seal is damaged, replace the balljoint.
5. The lower balljoints employ a visual wear indicator (see illustration) that allows easy diagnosis. The should at the base of the grease fitting protrudes about 0.050-inch (3/64-inch) from the lower surface of the balljoint's lower cover when the balljoint is new. As the balljoint wears, this shoulder slowly moves up into the balljoint. If the shoulder is flush with or inside the surface of the lower cover, replace the lower balljoint.

Subject: 1991, 1992, 1993, 1994, 1995, 1996 Chevrolet Impala SS, Caprice, Buick Roadmaster service, maintenance, repair. ISBN-10: 1563922495 | ISBN-13: 9781563922497 | Haynes 24046