WEICHAI & PSI SERVICE MANUALS AVAILABLE ONLINE AT FLYPARTSGUY.COM ADJUSTABLE PARAMETERS This engine has been certified by the US EPA to operate on pipeline quality commercial Natural Gas fuel as well as commercial LPG/propane. The Fuel System is non-adjustable and it can compensate for changes within commercial fuels at different locations in the US. Customers can use a fuel switch (PG Switch in Figure 19) to switch between NG and LPG operation. The default setting is for NG, the other position “PG” is for fuels with LPG/VPG (short Engine Interface Pin G & R). Figure 19 Fuel Switch for Different Fuel BTU Ranges WARNING:
ADJUSTMENTS MADE TO THE FUEL DELIVERY SYSTEM WILL INFLUENCE THE TAILPIPE EXHAUST EMISSIONS. IT IS THE OWNER/OPERATOR’S RESPONSIBILITY TO TEST THE SPECIFIC FUEL TYPE AT EACH SITE OF INSTALLATION AND DETERMINE THE CORRECT FUEL SYSTEM SETTINGS. Fuel Pressure Fuel Pressure need to be checked for the first start as in the Table 1 Table 1 EPR inlet pressure specification FUEL SYSTEM DIAGNOSTIC FUEL SYSTEM DESCRIPTION The Engine Control Module (ECM) receives information from various engine sensors in order to control the operation of the Integrated Electronic Pressure Regulator (EPR) and Shut-Off Valve. The Shut-Off Valve solenoid prevents fuel flow unless the engine is cranking or running.
At Key ON, the DEPR valve receives a two (2) second prime pulse from the ECM, allowing time for the fuel to flow through the fuel filter and fuel lines to the IEPR. The fuel is then to the Mixer. Engine cranking generates vacuum which provided lift for the mixer air valve and is commonly referred to as air valve vacuum. Once in the mixer, the fuel is combined with air and is drawn into the engine for combustion. WEICHAI EMISSION-RELATED INSTALLATION INSTRUCTIONS GET YOUR WEICHAI & AFTERMARKET SERVICE PARTS AT FLYPARTSGUY.COM Maximum EPR Pressure kPa 6.9 Minimum EPR Pressure kPa 1.5