|reply to alkizmo |
Re: Engine stalling when Brake Booster line disconnected
Just for clarification, there are two methods for measuring air on fuel injected vehicles. Mass airflow sensors (MAFs), and Manifold absolute pressure sensors (MAPs).
A MAF based engine will run poorly with a large vacuum leak as the engine is sucking in un-metered air. The motor will run leaner and can die out.
A MAP based engine will run just fine, only faster with a large vacuum leak. The MAP sensor is located in the intake manifold and measures the manifold pressure. A vacuum leak into the intake manifold just increases the intake pressure which the ECU will read and compensate for. Because you're bypassing the throttle and injecting air in after, it revs higher, it's just like pressing the gas a little.
That's where the discrepancy between online instructions are coming from, where some say it will run worse, others say it will run better.