This DIY repair and service manual by Haynes, covers the following Chevrolet automobile models:
- Chevy Lumina, 1995-2001
- Chevy Montecarlo, 1995-2005
- Chevy Impala (front-wheel drive), 2000-2005
Note: this manual DOES NOT include rear wheel drive Impala models or information specific to supercharged models.
Book Excerpt: 1995-2005 Chevrolet Lumina, Monte Carlo, Impala Repair Manual
VACUUM GAUGE DIAGNOSTIC CHECKS
A vacuum gauge provides valuable information about what is going on in the engine at a low cost. You can check for worn rings or cylinder walls, leaking head or intake manifold gaskets, incorrect carburetor adjustments, restricted exhaust, stuck or burned valves, weak valve springs, improper ignition or valve timing and ignition problems.
CHASSIS ELECTRICAL SYSTEM
Unfortunately, vacuum gauge readings are easy to misinterpret, so they should be used in conjunction with other tests to confirm the diagnosis.
Both the gauge readings and the rate of needle movement are important for accurate interpretation. Most gauges measure vacuum in inches of mercury (in-Hg).
As vacuum increases (or atmospheric pressure decreases), the reading will increase. Also, for every 1,000-foot increase in elevation above sea level, the gauge readings will decrease about one inch of mercury.
Connect the vacuum gauge directly to intake manifold vacuum. Be sure no hoses are left disconnected during the test or false readings will result.
Before you begin the test, allow the engine to warm up completely. Block the wheels and set the parking brake. With the transmission in Park, start the engine and allow it to run at normal engine speed.
The electrical system is a 12-volt, negative ground type. Power for the lights and all electrical accessories is supplied by a lead/acid type battery which is charged by the alternator.
This chapter covers repair and service procedures for the various electrical components not associated with the engine. Information on the battery, alternator, ignition system and starter motor can be found in Chapter 5.
It should be noted that when portions of the electrical system are serviced, the negative battery cable should be disconnected from the battery to prevent electrical shorts and/or fires.
CAUTION: On models equipped with a Theftlock audio system, be sure the lockout feature is turned off before performing any procedure which requires disconnecting the battery.
ELECTRICAL TROUBLESHOOTING: GENERAL INFORMATION
(Refer to illustrations 2.5a, 2.5b, 2.6, 2.9 and 2.15)
A typical electrical circuit consists of an electrical component, any switches, relays, motors, fuses, fusible links or circuit breakers related to that component and the wiring and connectors that link the component to both the battery and the chassis.
To help you pinpoint an electrical circuit problem, wiring diagrams are included at the end of this Chapter.
Subject: 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 Chevy Lumina, Monte Carlo, Impala service, maintenance, repair. ISBN-10: 1563926326 | ISBN-13: 9781563926327 | Haynes 24048