Turbo Diesel Registry
Issue link: http://read.uberflip.com/i/594528
114 www.turbodieselregister.com TDR 90 300,000 AND COUNTING Okay, you've seen many photographs of trucks owned by the TDR's writing staff. We had a member inquire, "What does Andy Redmond drive?" Drum roll, please, here it is. This is my '95. It has a gaggle of modifications. A few of which are: death wobble elimination, various "go faster" goodies, and rear illumination (nice in the dark when backing up). The exterior seems pretty stock—you may notice the addition of Second Generation mirrors and door moldings and the Third Generation wheels. It's probably fairly benign by most TDR members' standards, but it's to my liking. It does have several old-school, positive attributes: no OBD II, no LIN Bus, no Can Bus, nor is it equipped with a NOx catalyst or diesel particulate filters. Best of all, it is paid for. How long will it go? Who knows. Is it for sale? Nope, it's family. HOW E(empty) IS THE "E"? A complaint of an inaccurate fuel gauge on Second Generation 12 or 24-valve Turbo Diesel could certainly be on the top-ten list of owner complaints. The typical scenario: an owner notices that the instrument panel gauge reads full shortly after refueling, then quickly moves to "E" or perhaps the "one-quarter" tank mark until the tank is topped. Others complain of the "e" reading, irrespective of fuel level. Occasionally, a complaint will be a gauge reading of one-fourth tank, the low fuel lamp not illuminated, but the engine has died and the truck is out of fuel. The problem almost always involves the fuel tank's sending unit. The sender failure is usually one of two things: the sender electronics fail or the float arm/float fails. The electronics side includes a printed circuit board that acts as a variable resistor—the circuits become open (dead spot) or are biased (improper voltage for a given position). Likewise the sender's float is often eroded on the sender's arm and/or has fallen off the arm (gauge reads "E" always). My opinion is that ULSD fuel hastens the demise of the plastic float. I often find them detached and aimlessly floating about. Through the years, we've seen TDR members offer repair tips for the existing unit such as fasteners to increase/stabilize the tension on the variable resistor's wiper contacts or modifying a new sending unit. To remove a fuel sending unit is a major pain—drop the tank or lift the truck's bed. Either way, access to the sending unit is going to be dirty and time consuming. You don't want to do this job twice, so my recommendation for repair is to simply replace the sending unit with the appropriate Mopar part , which has been " improved" and superseded (and also improved?) many times. With a quality scan tool or digital multimeter the diagnostics are fairly simple. Of greater importance is an understanding of the principle of operation. • The '98-'02 truck uses a 240 ohm sender (0 at full, 240 at empty), so the sender acts as a variable resistor. • Make sure you have the correct part. It is possible to install the incorrect part. It will physically fit and function, but it will not be accurate. Examples: the sender for a 12-valve is 0 to 120 ohms, there are different units based on fuel tank size and someone may have made updates or changes to the fuel system. In previous TDR magazines we've had input from repair shop locations and we've scattered the articles throughout the magazine. In this issue my thanks again goes to TDR Writer and ASME Technician Andy Redmond. Andy operates a one-man, specialized repair shop in the north Dallas, Texas, suburb of Plano. I'm hopeful you'll enjoy the insight that Andy brings to the magazine.