Fuel System

If you own a 2013 or newer Ram and start your truck to discover a new message on your EVIC: "Service DEF System See Dealer", you'll think, “Well, what I am in for now?” See how this panned out for our own Brandon Parks... Reading this may possibly save you some worry, and even, a lot of money.

It could happen to you. The TDR editor discusses that dreaded and worrisome situation if/when someone mistakenly pumps gasoline into your diesel tank.

If the water-in-fuel light comes on, the first thing to do is to stop driving the truck. Repeat, STOP driving the truck.
The second thing to do: read this.

CP4 Preventive Maintenance: Here are some preventive measures you can follow by TDR writer Stan Gozzi.

We all see much discussion on the TDR web forums and in the TDR publications regarding performance/drivability issues, which are often traced to a low pressure fuel delivery problem. Although the narrative that follows is specific to the 12-valve Turbo Diesel trucks, model year 1994 to early 1998 (pre 24-valve engine), the discussion on the components from the fuel tank (float and sending unit) to the fuel transfer pump apply to all Second Generation trucks. Read on for more information.

What is an accelerator pedal position sensor (APPS) and is it not simply a throttle position sensor (TPS)? Good questions. The ’94-’98 models equipped with a 12-valve engine and an automatic transmission utilized a TPS. This sensor controlled shift timing and overdrive lockup. The 1998.5-to-present turbo diesels utilize an APPS for engine control and it provides input for automatic transmission (if so equipped). The 2005 to present Turbo Diesels continue to utilize the APPS. However, the sensor has been moved inside the truck and is part of the throttle pedal assembly.

Let’s go back to the easy-to-understand ’94-’98 12-valve engine. The TPS is actually a rheostat or potentiometer, with three electrical terminals [reference voltage, ground (called a return in most Mopar service info) and signal]. The signal has a varying voltage relative to throttle position, less at idle and more at wide open throttle (WOT). Example: at idle 0.6 volts

We all see much discussion on the TDR web forums and in the TDR publications regarding performance/drivability issues, which are often traced to a low pressure fuel delivery problem. Although the narrative that follows is specific to the 12-valve Turbo Diesel trucks, model year ’94 to early ‘98 (pre 24-valve engine), the discussion on the components from the fuel tank (float and sending unit) to the fuel transfer pump apply to all Second Generation trucks.

The term low pressure fuel delivery system covers the components from the fuel tank up to the truck’s fuel injection pump and from the injection pump back to the fuel tank. Common problems that will be discussed:

• Fuel level sending unit
• Fuel heating element
• Fuel transfer pump
• Overflow valve
• Fuel return line

Let’s start at the

The Cummins diesel is a longevity engine. When serviced properly, the engine should last 500,000 to a million miles between teardowns. Peripherals like the turbocharger, fuel injectors and the fuel pump, however, can wear out or fail much earlier. A well maintained fuel system can keep injectors going for 250,000 miles or more. Long injector life depends upon adequate fuel supply, quality fuel filtration and clean injector components. In addition to routine fuel filter changes...