Bruce Amacker Posted February 9, 2016 Share Posted February 9, 2016 I had a guy in class last week that's a dyno operator at Jasper. He says when a return line is not pressurized (due to a leak) on a 6.7 the hydraulic coupler in the injector won't function right and the engine runs like a turd. Has anyone heard of this? He seemed very knowledgeable and claims firsthand experience on this problem. They had a seeping return line which made an engine run poorly on the dyno and couldn't figure it out. They didn't realize the two were connected until they fixed the leak...... Quote Link to comment Share on other sites More sharing options...
lmorris Posted February 9, 2016 Share Posted February 9, 2016 Which return line is he talking about? I know that if the black line off the injector is leaking it can damage the injector, which I don't think is a return line more so than it is used to provide pressurized fuel to the injector cup in order to protect it from hammering itself to death. I neglected to make sure the return line to the tank was fully seated on the last one I had apart and it ran fine, other that the couple of gallons of fuel on the floor. Good way to bleed the system IMHO.... Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted February 10, 2016 Author Share Posted February 10, 2016 The injector return line assy which is connected to all 8 injectors. From the CTB: Injector Low Pressure Connectors The injector low pressure connectors have a dual purpose. First, it is a low pressure back feed to keep fuel pressure inside the hydraulic coupler. Without fuel pressure in the hydraulic coupler, the injector will not deliver fuel. Second, it is a return. The fuel that passes through the injector during the injection process exits the injector through the low pressure connectors and is returned through an orifice to the inlet of the secondary fuel filter. We're both right. I had forgotten about it's importance in keeping the coupler fed..... 1 Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted February 10, 2016 Share Posted February 10, 2016 Interesting. But in the real world I imagine that a customer would be complaining about a fuel leak before noticing a power loss. Don't you think? Point is I doubt this is something we will ever run into. Good to know though! Quote Link to comment Share on other sites More sharing options...
8WA Sman Posted February 10, 2016 Share Posted February 10, 2016 Interesting. But in the real world I imagine that a customer would be complaining about a fuel leak before noticing a power loss. Don't you think? Point is I doubt this is something we will ever run into. Good to know though! My experience with installing Jasper products has been that one may likely get an education on a problem that more knowledgeable techs then me had never heard of or only dreamed of. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted February 10, 2016 Share Posted February 10, 2016 I duuno... you seem plenty knowledgeable, especially for a guy that has jumped off of the dealership wagon. You seem to keep up just fine IMHO. Quote Link to comment Share on other sites More sharing options...
8WA Sman Posted March 14, 2016 Share Posted March 14, 2016 My new quote should be... In the unlikely posibility that anyone might perceive me as being knowledgeable , it is not because of anything I tried to teach myself it's because all of the weird stuff I've seen. I also was very fortunate to have smart mentors. Quote Link to comment Share on other sites More sharing options...
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