The High Energy Ignition (HEI) distributor with Electronic Spark Timing (EST) is used on the all Fiero models, except the 1987-88 2.5L L4 engines which uses the Direct Ignition System (DIS) that is distributorless. The HEI distributor incorporates all ignition components in one unit, except the coil in some instances.
- When making compression checks, disconnect the ignition switch feed wire at the distributor by releasing the locking tab and gently pulling downward.
- No periodic lubrication is needed because the bearings are lubricated by the engine oil.
- The tachometer (TACH) terminal is next to the ignition switch (BAT) connector on the distributor cap.
- Dwell adjustment is controlled by the ignition module, and cannot be adjusted.
- When adjusting the ignition timing, never pierce the soft spark plug wires. The spark plug wires are routed so they will not become scuffed or burnt. The wire must be routed in their original locations to prevent this condition.
REMOVAL & INSTALLATION
- Disconnect the negative (-) battery cable. Remove the ignition switch battery (BAT) feed wire and tachometer lead from the distributor.
- Remove the distributor cap by turning the four latches counterclockwise. Move the cap out of the way.
- Remove the four terminal ECM harness connector from the distributor.
- Mark the position of the rotor on the distributor housing with a grease pen or permanent marker. Mark the position of the distributor housing at the engine block by scratching a mark with a screwdriver or equivalent.
To ensure correct timing of the distributor, the distributor must be installed with the rotor and housing correctly. The ignition timing will have to be checked with a timing light after the distributor is installed.
- Remove the distributor hold-down bolt and retainer. While twisting the distributor housing, pull upward and remove the distributor.
If the distributor will not move, spray some penetrating oil around the base where it goes into the engine and wait a few minutes for the oil to penetrate.Engine Not Rotated
- Rotate the distributor shaft until the rotor aligns with the second mark you made (when the shaft stopped moving). Lubricate the drive gear with clean engine oil, install the distributor in the engine.
- Install the clamp and hold-down bolt. Tighten them until the distributor can just be moved with a little effort.
- Connect all wires and harnesses and install the distributor cap.
- Set the timing and tighten the hold bolt. Refer to the "Ignition Timing" procedures in .
If by chance, the engine crankshaft has moved while the distributor was removed. Refer to the following procedures to properly set initial timing so the engine will start.
- Remove the No. 1 spark plug. Refer to the Firing Order illustrations for No. 1 spark plug location.
- With the engine cool, place your finger over No. 1 spark plug hole and crank the engine slowly by hand until compression is felt.
- Align the timing mark on the crankshaft pulley to the 0 mark on the engine timing indicator.
- Turn the rotor to point at the No. 1 spark plug tower on the distributor cap.
- Install the distributor and connect the ignition feed wire.
- Install the cap and spark plug wires.
- Check and adjust the engine timing with a timing light to proper specifications. Refer to the Ignition Timing procedures in .