This Haynes DIY repair manual covers 1970-1981 Pontiac Firebird models, equipped with 265, 301, 305, 350, 400, 403, and 455 cid V8 engines, including:
- Firebird Trans Am
- Firebird Formula
- Firebird Esprit
Note: this manual DOES NOT include turbocharged engines.
Book Excerpt: 1970-1981 Pontiac Firebird Repair Manual
ENGINE ELECTRICAL SYSTEMS
PRE-1975 IGNITION SYSTEMS
The ignition system is divided into two circuits: the low tension circuit and the high tension circuit. The low tension (sometimes known as the primary) circuit consists of the battery lead to the starter motor, lead to the ignition switch, calibrated resistance wire from the ignition switch to the low tension or primary coil winding, and the lead from the low tension coil windings to the contact breaker points and condenser in the distributor.
The high tension circuit consists of the high tension or secondary coil windings, the heavy ignition lead from the center of the coil to the center of the distributor cap, the rotor, and the spark plug leads and spark plugs.
The system functions in the following manner. Low tension voltage is changed in the coil into high tension voltage by the opening and closing of the contact breaker points in the low tension circuit.
High tension voltage is then fed via the brush in the center of the distributor cap to the rotor arm of the distributor cap, and each time it comes in line with one of the 8 segments in the cap, which are connected to the spark plug leads, the opening and closing of the contact braker points causes the high tension voltage to build up, jump the gap from the rotor arm to the appropriate segment and so, via the spark plug lead to the spark plug, where it finally jumps the spark plug gap before going to ground.
- The lock cylinder is located on the upper right-hand side of the steering column. On models built in 1970, the lock cylinder can be removed in any position from "ACCESSORY" to "ON" but removal in "LOCK" position is recommended. From 1971 on, the lock cylinder should only be removed in the "RUN" position, otherwise damage to the warning buzzer switch may occur.
- Remove the steering wheel (Section 15 or 16) and directional signal switch (Section 21). Note: The directional signal switch need not be fully removed provided that it is pushed rearwards far enough for it to be slipped over the end of the shaft. Do not pull the harness out of the column.
- Insert a thin blade or driver into the slot in the turn signal switch housing. Break the housing flash loose and at the same time depress the spring latch at the lower end of the lock cylinder. Holding the latch depressed withdraw the lock cylinder from the housing.
- The lock cylinder cannot be dismantled; a new one (coded to accept the original key) must be installed in the original cylinder sleeve after the assembly has been dismantled by releasing the cylinder to sleeve staking.
- To assemble the new lock cylinder to the sleeve, insert the ignition key part way into the lock and then place the wave washer and anti-theft ring onto the lower end of the lock cylinder, making sure that the plastic keeper in the sleeve protrudes.
Subject: 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981 Firebird Trans Am, Formula, Esprit service, maintenance, repair. ISBN-10: 085696882X | ISBN-13: 9780856968822
Also available: 1973, 1974 Firebird Sales Brochures.