Multec 3.5 Fuel Injector Application Manual Testing Recommendations and Precautions
Delphi Energy and Chassis Systems
Revision: 11/05-1 8-1
8.0 Testing Recommendations and Precautions
Every vehicle/engine manufacturer has a developed set of standard test
procedures for component validation. Since most are unique and
proprietary to the manufacturing company, there will not be an attempt to
list them all here. Instead, some general examples specific to injectors are
provided.
8.1 Dynamometer Testing
It is critically important that the Multec 3.5 Fuel Injector be tested under
conditions that approximate normal operating conditions to ensure that
fueling is accurate. A dynamometer is an ideal facility to set steady state
engine conditions for evaluation. The following are a few topics that are
important to investigate.
Caution
The dynamometer engine fuel supply should be properly filtered to
prevent contamination of the injector. (See section 7.3.4.)
Vibration levels generated on a dynamometer engine may significantly
exceed those generated in actual vehicle usage. Dynamometer engines
used for durability testing should have the vibration levels measured and
compared to those in the actual vehicle application. Excessive vibration
levels can result in accelerated injector wear.
8.1.1 Cylinder-to-Cylinder Distribution
Cylinder-to-cylinder air/fuel distribution should be tested in a
dynamometer environment. Thermocouples should be inserted into each
exhaust port so temperature can be monitored, along with air/fuel ratio,
and emissions variation. Rail flow distribution, manifold airflow
distribution, and EGR distribution should be included in addition to
injector flow in any cylinder-to-cylinder air/fuel ratio investigation.
8.2 Durability Testing
Real world durability tests are performed in an application environment
and conditions specified by the manufacturer (i.e., on vehicles). These
tests should evaluate the range of environmental and fuel conditions
expected in customer usage. The application’s environmental stress levels
can be compared to those previously used for Multec 3.5 testing to
determine whether additional durability evaluations are required.
In addition, Delphi conducts generic bench injector durability testing to
determine injector useful life. The generic test schedules are intended to
comprehend the worst case customer usage.
To Next Page
Loading...
Need help?
General