If the engine in your 1989 Dodge D150 Ram with a 5.2 liter engine is pinging under acceleration and the mileage is very poor what is wrong?
Check the timing first. Then check the egr ooperation. Then check the compression wet and dry. Run some engine cleaner through it.
The "Dodge" diesel is actually a Cummins heavy truck engine. With proper maintenance, it should last about 250,000 miles. The injectors will need replacing every 100,000 miles. I would say 500,000 is average for the engine. I do not agree about the injectors. The truck will wear out before the engine does.