15 Oct Diesel Engine Tune-Ups

Posted at 09:22h in Truck Repair Tips by
  • On the CAT 3406 set the valves, set the jakes, check the pump timing.
  • On the CUMMINS N Series check the valve adjustment, adjustments should be made cold, Then the Jakes.
  • On DETROIT Series 60 First start with a cylinder leakage test, adjust valves, set jakes, the Detroit engine has a procedure list longer than any other engine. To describe the procedures for the leakage test is quite long.

A diesel engine is by far better than a gasoline engine, but when it comes time for a tune-up, there’s more involved with the diesel engine. Some of the things to start with are compression readings from each of the cylinders, an engine that runs rough may have low compression, which can be caused by misadjusted or leaking valves.

Over time the engine timing may change, which will affect starting, power, rough or erratic idle. One way to check a rough motor is to bring the truck up to operating temp, and loosen the fuel lines at the injectors one by one, if you loosen one and the engine gets rough, retighten and move on. If you find nothing at the injectors you may want to check the timing.

If you find one that doesn’t change the pitch, you may also have a fuel injection problem. If you have to pull the injectors remember this tip: The orifice of the injector is the most important part, any clog or damage to the orifice can change the spray pattern and reduce the injector’s performance.

Any time you handle an injector, you must take care to avoid hitting the tip against a solid object, dropping it or setting it down on the nose. If the injector has been dropped, don’t assume that because there is no visible sign of damage it still is in perfect condition.

Return that injector for testing and get another one, if the orifice has been exposed to dirt or grease, you can’t just clean it because the contaminant may have become lodged inside the orifice. Again return the injector for testing and get a new one.

The above steps only sound like a few steps but to perform these steps is quite involved, performing these steps on your engine will help optimize fuel economy and save money down the road.