7. Intake Restriction

7. INTAKE RESTRICTION

Purpose:
This purpose of this test is verify an air intake or exhaust restriction is not contributing to a low power condition. If the engine does have a high air intake restriction, a considerable amount of black or blue smoke may be produced.

Intake Restriction
- Check air filter restriction gauge/indicator.
- Measure the vacuum on clean side of air inlet system at wide open throttle (WOT) with a Magnehelic(R) gauge.







Recommended Procedure:
Inspect the air cleaner inlet and ducting to make sure it is not blocked or collapsed. Inspect the air cleaner housing and filter for proper installation.

Inspect for any indication of water intrusion into air cleaner/filter.

If necessary, use DSL ENG Pressure Test Kit 014-00761 or equivalent to install a Magnehelic(R) gauge on the port on the air cleaner and measure restriction at high idle.

Air Filter Restriction Gauge:

Magnehelic(R) Gauge:

Possible Causes:
- Snow or other foreign material may restrict airflow at the air inlet
- Misrouted air cleaner ducting
- On engines recently repaired, rags or cap plugs may have been inadvertently left in an air inlet pipe

Tools Required:
Magnehelic(R) gauge (part of DSL ENG Pressure Test Kit 014-00761 or equivalent)