This Chilton repair manual covers 1989-1996 Dodge Ramcharger and Dakota, including 1/2, 3/4, and 1-ton pickup trucks, 2WD and 4WD with gasoline and Cummins diesel engines.
Book Excerpt: 1989-1996 Dodge Dakota, Ramcharger, 1/2, 3/4 and 1-Ton Pick-Up Truck Repair Manual VALVE SEATS: REMOVAL and INSTALLATION

See Figure 112 If the valve seat is damaged or burnt and cannot be serviced by refacing, it may be possible to have seat machined and an insert installed. Consult an automotive machine shop for their advice. Diesel engine valve seats can be ground only once. If the seat has been reground, service seats must be installed. One X stamped into the head identifies that the seats have been refaced. If the wall stamp is XX, it means service has been installed. Service seats can be reground. If you remove more than 0.010 in. (0.254mm) from the cylinder head combustion surface, install service seats. Measure the head height to determine if service seats are necessary. Check the rear lower right corner of the head for stamping that would indicate previous resurfacing. The valve depth limit is 0.010 in. (0.254mm).

MULTI-PORT FUEL INJECTION (MFI) SYSTEM: GENERAL INFORMATION

The sequential Multi-port Fuel Injection (MFI) System was introduced on all 3.9 and 5.2L engine-equipped models in 1992. As of the 1993 model year, all gasoline powered engines except the 2.5L were so equipped. The 2.5L engine was MFI-equipped for the 1996 model year. The MFI system is controlled by a pre-programmed digital computer known as the control module on 1992 models, or the Powertrain Control Module on the 1993-96 models. As with the TBI system it replaced, the MFI system computer controls ignition timing, air/fuel ratio, emission control devices, charging system and idle speed. The computer constantly varies timing, fuel delivery and idle speed to meet changing engine operating conditions. As its name would imply, the chief difference of the MFI system is the utilization of individual fuel injectors at each cylinder. These injectors spay fuel in precisely metered amounts into the intake port directly above the intake valve. They are fired in the correct sequence by the ignition controller which constantly reads conditions in order to maintain the ideal air/fuel ratio (stoichiometric) of 14.7:1. By adjusting the length of time the injector opens and sprays fuel into the chamber (pulse width), the proper air/fuel ratio is maintained which greatly helps increase power, drivability and emissions. The primary variables that the engine controller uses to determine pulse width are manifold absolute pressure (air density) and engine rpm (speed). In addition to manifold absolute pressure (MAP) and engine speed (rpm), the engine controller also considers input from the following sensors to determine the pulse width:

• Exhaust gas content
• Coolant temperature
• Throttle Position
• Battery voltage
• Air conditioning selection
• Transmission gear selection
• Speed control

Subject: 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996 Dodge Dakota, Ramcharger, 1/2, 3/4 and 1-Ton pickup truck service, maintenance, repair. ISBN-10: 0801988470 | ISBN-13: 9780801988479