The 1990 Ford 7.3 engine mainly has starting problems. It takes a great deal of time for the engine to start, although after starting, one can go for long hours without experiencing other problems. This is usually caused by air intrusion in the fuel filter.
The other problem that mars the performance of Ford 7.3 engine is overheating, possibly as a result of radiator, thermostat, water pump or cooling fan-related problems. The thermostat and the water pump are the most frequent causes of overheating, but these parts are easy to replace and fix.
On other occasions, the fuel heater can short out and blow the fuse. The way to fix this is to disconnect the fuel heater, replace the fuse and restart the engine.
The injector driver module located in the driver’s side fender can go bad or get damaged from water that would cause failure to start or rough running once the engine has started. Another problem that frequently arises occurs when the under valve cover harness connectors become loose. They can cause rough running conditions that make the truck lope badly and may also cause sputtering. Frequent checks and repairs of damaged connectors are needed to solve this problem.