When you’re dealing with a no-start complaint on a gas engine, you only have three things to check. Is it getting fuel? Is it getting spark? Can the engine compress the air/fuel mix?
But on a diesel, it’s another story.
First, there’s no spark plug or ignition system to consider. Diesels are compression ignition engines. They rely on high compression pressure to heat the air/fuel mix to the point of combustion. Cylinder pressures can rise to 500 psi or more as compared to a high of 200 psi on a gas powerplant.
As for fuel, the injection methods used are a lot different than the port-injected or Gasoline Direct Injection (GDI) engines you have in your shop. All require high-pressure injection similar to GDI but it’s HOW that high pressure is generated you need to understand and apply in your diagnostic process.
And testing compression? That is a challenge all in itself! With no spark plugs to remove, you’ll have to go in via the glow plugs or injectors to take a mechanical compression reading - or do you?
Maybe it's these reasons that many gas guys (and gals) shy away when a customer brings in their diesel-powered vehicle. If that’s the case, then watch this month’s edition of “The Trainer”! I think I can show you that you are more than capable of dealing with anything your customer may throw at you.
And to learn more about the tools used in the video, visit www.Autel.com.
