I have a 2002 gmc sierra 2500hd 6.6 diesel the trucks eng. cranks but dose not start, but if i spray starter fluid into the air filter it starts and stays runing good with no problems, but every time i shut the eng. off it dose not start.. and i already replaced the fuel filter!

sounds like starter motor/solenoid problem, try hitting the starter motor with a hammer , a couple of sharp hits may loosen off the bendix if this is the problem, if starts replace the starter motor

Have you checked the Solenoid? That would be why the starter would keep engaging, but not start. You might also want to check the Voltage Regulator, and the sensors. Here is a page of images that might help you with identification.


2002 GMC Sierra 2500HD solenoid Google Search

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suggest you look at a bunch of these youtube videos .

try to check your starter and ignition.
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wires broke under fuel filter is the water in fuel sensor.need to replace water in fuel sensor install new fuel filter pump the primer located on top fuel filter 30 times until stiff then try to start truck.the water fuel sensor got damaged became loose leak out fuel in fuel filter causing hard start problems, diesel engine wont start if air in fuel system or air filter stopped up.

could be stopped up air filter, fuel filter, or weak fuel pump...try cycling the ignition on several (3 or 4) times and see if it starts any faster...sign of a weak fuel pump.

I would lean towards the fuel pump, but... How dirty was the old filter??? if it was bad then the new one may have picked up whatever was left in the line. I guess I would go the easy route, replace the fuel filter, this time with the filter off crank the truck and catch the fuel in a mason jar til it is clean, you may need to drain the tank and try to clean it out if it is real dirty. Hope this helped Tim

becarfull, the fuel filter os on the passenger side of the engine compartment. after replacing the fuel filter you need to prime the system to get all the air out of the fuel system otherwise the engine will crank and crank and never start. if this happens, you'll need how to prime the system or tow the truck to the nearest Gm dealership.
read the owners manual for help.

replace fuel filter.check fuel pressure.

I would start by changing the fuel filter. The next area would be the O-rings if so equipped. If it starts better after a short use then you are getting air in the fuel lines overnight. Diesels are tempermental. The cranking speed of the starter is important and easily checked externally. If you have a mechanical fuel pump you are relying on cranking speed to prime the fuel system. The timer or timing wiring could prevent the glowplugs from heating up. Diesels rely on glowplugs to start, then compression to run. Its a lot to look at but I suggested the cheapest fixes first.