I have a 2005 gmc Sierra 2500hd 6.6 duramax diesel crewcab with approximately 90,000 miles on it. After sitting for a while (9 days in cold weather -18C) I tried to start it (about 3-4 seconds) and after the engine turned over I heard a presure relief noise (about 1 second...ptsssss). It turned over fine but no ignition. I have replaced the fuel filter, primed the system (3 times), that did the trick......for about 2 days (3.5hour run time). Driving down the road (30 mph) and the engine dies. Will not start. Agian, it was a cold day. Any ideas? Spike

SOURCE: 2003 GMC Duramax Diesel won't start

I see that you had the injectors replaced 20,000 miles ago. I would still check the oil to make sure it is not overfull. The new injectors could be bad. If the oil level is not overfull then get a paper towel and touch the dip stick tip on the paper towel while oil is on the dip stick. If it's only oil it will not spread. If it has diesel in the oil the oil with spread. If this test doesn't show the injectors to be bad then you have three other possibilities. The FICM (fuel injection control module), the fuel pressure regulator, or the injection pump. It's hard to pinpoint what the problem is without running more tests and the only way to run those tests is with the computer the dealership has. Just so you know your injectors are still under warranty until 100,000 miles. Most likely you will have to take it to the dealership to get you truck fixed. I hope this helps you some.