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Discussion Starter #1
I have been stumped for a while on my lml duramax. When my truck sits for more than 4 or 5 hours it has a fuel issue, or what I think is a fuel or prime issue. It will crank fine, idle up and warm up... Everything is fine so far. Pull out of my driveway ( about 200 yards) open my gate, pull up shut it and drive off... This is the point the issue shows itself. It start to sputter and lose all power. It doesn't shut off but smokes some blueish smoke and has no power. And it just feel like a fuel starvation problem. At this point I put it in park and turn it off. I crank it back up and not a problem in the world.... I put a fass 165 lift pump on it and it was sucking air out of the stock suction line so I put a beans diesel sump. No air going to the fass. Already rebuilt the original filter and put on a new filter. No diesel leaks that I can find up in the engine. Sorry for the long post but I cannot find a thread that had the same exact issues as mine. Thanks in advance for taking your time to read this nonsense!馃槄
 

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Many problems reported with FASS 165 putting out too much pressure. Look for other posts talking about adjusting the pressure to ~7-8 lbs and make the adjustment. Then see if problems still occurs and let us know.
 

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Discussion Starter #3
I had the problem before I installed the pump. It runs smoother and better after I installed the fass. But still has the problem. My hope in installing the lift pump is I could find a leak in the engine bay from a hole in the line. In the mindset it was air in the lines or something of that nature. Pressuring the line would identify it. It has not.
 

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Discussion Starter #4
I think I wasn't clear on the post that all the things I do was trying to fix the sputtering problem. The first thing I did was rebuilt the primer housing and new filter. The second thing I did was put a fass 165 on it, it was sucking air out of the stock fuel tank suction line. I was thinking at that point I found the problem so I dropped the tank and tried to find the leak. I couldn't, so I put a sump on the tank, it doesn't suck air anymore but the problem still exists. I wanted to pressurize the lines to see if there was a leak anywhere. So imo the fass pressure has nothing to do with it. I have a pressure gauge I'm putting on it but haven't yet.
 

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Discussion Starter #10
Just found a guy from another forum and get is fitting all the symptoms. Must be getting stuck. If I use a blocker will I have to get a tuner to clear it from the computer.
 
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