Engine Idle (Speculation)

When an engine will not idle or run correctly, a vacuum leak may be the culprit.

Such leaks allow:

• Unmetered air to enter the engine
• Upset the air/fuel ratio

leading to a disruption in the operation of the computer system and a wide range of symptoms.

An air leak should be suspected if:

• The engine idle speed it too fast
• If there is a rough engine idle or stalling
• If there is hesitation or misfiring upon acceleration

Vacuum leaks are frequently caused by deteriorated, broken, or loose vacuum hoses which are often difficult to pinpoint. Even a tiny leak, as small as 0.020 of an inch, can degrade engine performance, compromise drivability, and turn on your "Check Engine" light.

TIP: A vacuum leak often disguises itself as an ignition or fuel problem.

By reducing the optimal pressure and vacuum within an operating engine, a vacuum leak can inhibit the action and function of a car's carburetor and/or fuel injection system, which directly impacts vehicle starting.