TECHNICAL DETAILS The Gunson Lo Gauge Vacuum Tester is a petrol engine vacuum and fuel pump tester, ideal for diagnosing engine faults. When used as an inlet manifold vacuum tester, it can help identify issues such as spark misfires, poor compression, weak or rich mixtures, incorrect ignition timing (advanced or retarded), air leaks in the inlet manifold or carburettor, and incorrect valve timing.
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