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Ask Gm Tech (Cam) Your Own Question
Gm Tech (Cam)
Gm Tech (Cam), GMC Mechanic
Category: GMC
Satisfied Customers: 1693
Experience:  GM Grand Master Technician 2007. 14 year experience.
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GMC 2500HD: I have a 2005 duramax in a gmc 2500 hd after pulling

Customer Question

I have a 2005 duramax in a gmc 2500 hd after pulling a load on a hot day it either dies at idle or shortly after restarting it dies and won't restart. Tried bleeding fuel filter but didn't work last time. This is the 5th time it has done this.
Submitted: 2 years ago.
Category: GMC
Expert:  Gm Tech (Cam) replied 2 years ago.
Hello, I'm Cam.
Can I get your first name please?
Find the 2 fuel lines on the rear drivers side valve cover. Take the smaller one off and attach your hose to the metal pipe coming from the engine. Put the other end into the container and run the engine to fill that line. Then shut it off and remove the IGN 1 relay from beside the starter relay. empty out the container and keep the line full. Crank the engine for 15 seconds fully and measure the amount of fuel that comes out of that line. More than 24cc means the injectors have failed.
Customer: replied 2 years ago.
My name is***** will try to check this after work this evening. I haven't bled the system yet this time but if its injectors doing this it seems odd that it runs fine all Winter and has only done this in hot weather after pulling a load. Acts like a vapor lock on an old gas engine. But won't correct itself. Is there any area of the supply line exposed to heat that may have lost insulation?
Expert:  Gm Tech (Cam) replied 2 years ago.
KEvin, this has to do with the heat of the engine, expansion of the injectors and viscosity of the fuel. These all happen more when in summer months and when towing. The system starts to return more fuel to the tank causing the low pressure situation and this results. Do the test I outlined, and try to do it when hot. IT will give you a better sense of how much. You can also test at each injector, take the line off and capture the fuel from the top. 3ml per injector is the max allowed during the same 15 seconds of cranking.