Multec 3.5 Fuel Injector Application Manual
Recommendations and Precautions
Delphi Energy and Chassis Systems
Revision: 11/05-1 7-5
In addition to a fuel line filter, injector inlet filters also protect the
injectors from fuel system initial assembly contamination. The fuel
injector inlet filter is not designed to be serviceable and is not intended to
be the primary filter in the fuel system.
7.3.5 Fuel System Generated Contamination
The fuel system and injector inlet filters are present to collect particulate
contamination. Fuel soluble contaminants may be present in the fuel
system that can harm the injector or promote future deposit build-up.
Oils, lubricants, and rust inhibitors used during manufacturing are some of
the compounds that may be present in the fuel system (fuel lines, fuel rail,
fuel pump, fuel tank).
Substances of the types mentioned above should be evaluated by Delphi
for potential injector damage or deposit formation. Where the effect of a
substance is not known a production process sample may be required for
evaluation of the substance’s effect on the fuel injector.
Metal fuel lines should be stainless steel to prevent internal corrosion
products from aggressive fuel from damaging the injector.
7.3.6 Maximum Fuel Pressure
Caution
The fuel supply system must be designed to prevent failure modes that
expose the injector to pressures greater than 1000 kPa (145 psi.) A
system FMEA should be performed to verify the fuel injector is protected
from excessive pressure. Normally, a valve in the fuel pump protects the
fuel system from overpressurization. Injector pressures in excess of 1000
kPa may cause permanent damage to the injector.
7.3.7 Injector
Storage
Caution
It is not recommended that the injector be exposed to fuel then stored for a
significant period of time (> 3 months). A fuel stabilizer such as Sta-Bil
or equivalent should be added to fuel used for production engine hot
testing. Use the treatment rate of concentration of fuel stabilizer
recommended by the manufacturer.