DO NOT BUY ANOTHER OPTI YET
New does not mean proven
A replacement distributor can be defective, incorrectly installed, mis-indexed, or accompanied by a wiring/connector problem. Re-check the work before expanding the parts list.
LT1 · 1993 · POST-REPAIR
1993 LT1 Still Won’t Start After Optispark Replacement
If the problem started immediately after distributor work, verify the installation before replacing more parts.
APPLICATION: 1993 Firebird / Formula / Trans Am 5.7L VIN P LT1 with distributor/Optispark service history.
Starter kickback is a clue
If starter kickback begins immediately after distributor service, verify engine position and distributor indexing using the exact 1993 installation procedure. Base ignition timing is not a normal external adjustment on this system.
Prove reference activity
Confirm the distributor is receiving the required feeds and producing usable reference information before treating the replacement as good.
Post-repair sequence
- Confirm plug-wire routing and that no connectors, grounds, vacuum lines or harness sections were disturbed.
- Verify distributor mechanical installation/indexing against the 1993 service procedure.
- Inspect cap/rotor and connector condition.
- Verify distributor power/ground and high-/low-resolution reference activity.
- Then branch into ignition-control/coil output, fuel delivery or mechanical checks according to what is missing.
- Do not attempt to “fix” the symptom by rotating the distributor as if it were a conventional adjustable-timing distributor.