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Home >> Pontiac >> 1990 >> LeMans Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Basic Testing >> Diagnostic Charts >> Chart A-5 Fuel Pump Relay >> Diagnostic Aids

Diagnostic Aids

An inoperative fuel pump relay can cause long crank times before engine start. The long crank period is caused by time needed for engine to build oil pressure and energize fuel pump through back-up circuit.