ROUSH fuel rail assembly and flow control solenoid. The flow control solenoid is used by the Powertrain Control Module (PCM) to control fuel pressure in the fuel rail in order to ensure there is liquid propane in the fuel rail. The solenoid is a normally closed solenoid with an orifice drilled between the inlet and outlet ports of the solenoid body to permit some flow back to the tank when the solenoid is closed. When the solenoid is energized, the orifice is bypassed and return fuel flow to the tank is increased. Click to enlarge.

ROUSH CleanTech’s signature blue anodized aluminum fuel rails are designed to operate under the varying temperatures and pressures of liquid propane. Fuel is regulated from the tank by the FRPCM (Fuel Rail Pressure Control Module) then sent through the rails. Fuel is then injected into the engine by each of the ten fuel injectors. Un-used fuel returns through the FRPCM and flows back into the fuel tank.

The ROUSH CleanTech liquid propane autogas strategy is built off of the OEM strategy with the addition of new logic to drive and monitor the flow control solenoid. Because the strategy is based off of the OEM strategy, the OEM PCM retains all fuel control and diagnostic functions. No modifications are made to the scan tool interface features of the logic except to add the propane autogas specific DTC’s. The propane autogas DTC’s are stored in the PCM memory and are cleared via the OEM strategy’s fault state controller.

One of the key benefits of the ROUSH CleanTech liquid propane autogas fuel system is that vehicle operation and performance is virtually transparent as compared to that of the base gasoline vehicle.

Propane autogas is a lower carbon alternative fuel that reduces greenhouse gases by up to 25%, 60% less carbon monoxide, and fewer particulate emissions versus gasoline.

Historically, propane autogas costs 40% less than gasoline and up to 50% less than diesel. The current gasoline price MTS pays is $1.99 per gallon and the propane prices is $1.39 per gallon. The paratransit vehicles travel 40,000 miles annually and the minibuses travel 45,000 miles annually.

This is a great example of how MTS is realizing cost-savings and helping communities reduce emissions. MTS will save about $5.8 million over the five to seven-year lifecycle of the vehicles and reduce the carbon intensity by 71%.MTS CEO Paul Jablonski

All propane-fueled buses will be stationed at the agency’s Copley Park Division in Kearny Mesa where MTS operates 178 paratransit vehicles and 37 minibuses. In addition to paratransit services, the division covers 30 bus routes and serves about 1.3 million passengers annually. With the switch to propane, 35% of the Copley Park fleet is now operating on alternative fuel.

The California Air Resources Board and EPA certify the ROUSH CleanTech Ford E-450 and F-550 buses for sale in all 50 states. The ROUSH CleanTech Ford E-450 has completed Federal Transit Administration’s New Model Bus Testing Program (“Altoona Testing”) and can be purchased using a transit agency’s FTA funds.