Car Vacuum and Fuel Pump Tester Gauge Kit – Fuel Pump Pressure & Vacuum, Carb...

Car Vacuum and Fuel Pump Tester Gauge Kit – Fuel Pump Pressure & Vacuum, Carburetor Intake Manifold, & Vacuum. Steady, Regular Drop: Suggests an open, burnt, or chipped valve. Wide Pressure Fluctuation at High Speeds: Points to a weak valve spring.