With a diesel engine, a tune up isn't like a gas engine. Basically, you need to keep filters clean such as the fuel filter, air filter. As far as the injector pump, it is designed by the manufacturer to maintain a specific pressure.
If the vehicle is running rough, you may want to use a fuel additive for diesel engine to help keep injectors clean. Also, based on mileage, you may want to check timing.
Thursday, September 15th, 2011 AT 3:32 AM