My 2002 GMC Duramax LB7 won't start after I shut it off Already replaced the fuel regulator which the code came up Still have to crank and crank before it will start. Runs great once it's going. 160545 miles

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.

SOURCE: 2002 GMC YUKON XL 1500 MOTOR DIES AFTER GOING

Check the fuel cap!! If the vacuum relief is not working it can impede the fuel flow and cause the engine to shut down or not restart after a stop. Waiting usually gives things a chance to stabalize and the engine will restsrt. When this happens again try loosening the cap and see if the engine will restart.....If it restarts immediately, REPLACE the fuel cap..Do Not leave it loose because this will cause other problems. If it is not the fuel cap the problem may be the filter, the fuel pump, or aome other fuel system malfunction.

Testimonial: "Great will try it "

SOURCE: need a 2002 lb7 duramax firing order diagram

firing order is 12784563 cyl placement is drivers side front to rear 2468 pass side front to rear 1357

SOURCE: 2002 GMC 2500 HD Duramax starter will skip off

Check flywheel teeth. Might be missing some teeth on the flywheel. Remove starter and you should be able to see flywheel. Turn flywheel and check all teeth.

SOURCE: My 2002 GMC Denali XL doesn't like to start on the first crank

the fuel filter would be the first place i would go, especially if it has not been replaced recently. it can cause slow priming of the fuel pump, resulting in hard starting. in addition, if your truck has never been tuned up, a set of spark plugs could make the world of difference - i believe on your particular truck it is recommended to change them at least every 100,000 M. good luck!