Prime is not the whole test
The 1997 PCM initially turns the pump on with key ON. Continued pump operation while cranking/running depends on receiving engine reference pulses.
LT1 · 1997 · NO-START
1997 LT1 Fuel Pump vs Distributor Reference
The two-second prime can work even when the engine-reference system cannot keep the pump commanded during cranking.
APPLICATION: 1997 Firebird / Formula / Trans Am 5.7L VIN P LT1.
DO NOT REPLACE THE PUMP FROM THIS SYMPTOM
If the pump primes but quits during crank, determine whether the PCM is losing reference information before condemning pump hardware.
Branch it
- Confirm initial pump prime.
- Observe spark, injector pulse and distributor reference activity during cranking.
- If reference activity is absent, move into distributor power/ground/high-low resolution diagnosis.
- If reference is present but pump output disappears, diagnose pump relay/control/feed and the pump circuit.
- Verify actual fuel pressure rather than judging pump operation only by sound.
FPV RULE
OBSERVE → MEASURE → ISOLATE → PROVE → REPAIR → VERIFY. Do not turn a symptom, DTC or catalog fitment label into a parts order.
AFTER THE FAILURE IS PROVEN
Use the proven failed branch—not the original symptom—to choose the replacement. Go from diagnosis to the Parts Verdict →