Excessive fuel use
SUPPLEMENTAL DIAGNOSTIC PROCEDURES
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Excessive Fuel Consumption
Probable Causes
Customer Effects
Inaccurate record keeping or tank filling, winter blend or #1 fuel, high expectations.
Application Effects
Heavy loading (GVW), low rear axle ratio, large frontal area, prolonged idle times, accessory usage (PTO's et.), tire size.
Chassis Effects
Brake drag, Fan clutch engagement, transmission slippage/shifting, fuel tank plumbing and venting, intake or exhaust restriction.
Engine Effects
Incorrect or defective thermostat, faulty (EBP) Exhaust Back Pressure operation, oil aeration, fuel system leaks, base engine performance loss.
Procedures
Review customer records and fueling procedures. Fuel consumption determined from only one tank of fuel is susceptible to significant error because of filling procedures and vehicle application differences during operation. Accurate fuel consumption must be measured over time, preferably over four tanks of fuel with a record of what the vehicle was towing or doing during that time.
Loss of fuel economy is normal if winter fuels, kerosene or #1 diesel is being used.
Review vehicle specifications to determine if fuel consumption is normal for type of application and use of vehicle. (Compare consumption with similar vehicles in same application)
Conduct all tests on the Performance Diagnostic Sheet. These tests will test the following engine/chassis systems and determine if the following systems are functioning or if particular conditions are present. Intake and exhaust system, fuel delivery and filtration system, high pressure fuel system and injector operation, turbocharger and exhaust back pressure operation, oil aeration, base engine condition and electronic control system condition. If all tests are passed, the engine is operating normally.
I managed to look down between the turbo and fuel pump and can see fuel puddled on top of the intake manifold. I can't see where it's coming from with the engine running but a friend has suggested cracked fuel lines so we're going to figure out how to pull that stuff off and check there. It has to be coming from somewhere right in that area.
the leak may even be comming from one of the three short rubber fuel lines in going from the back of the fuel bowl to the fuel pump. with the change of weather, the rubber may have contrasted/expanded enough to produce a leak.



