2002 chevy 2500hd 6.0 gas, hard starting wether its dead cold or cooled off alittle bit

have you had a diagnostics test run on the truck's computer?

Diagnostic test and check fuel pressure.

0 codes on the code reader, have not checked fuel pressure at fitting.

Won't be a pressure issue. There is a one way check ball in your fuel pump that should keep pressure on the line and the fuel pressure regulator should be closed when the engine is off keeping pressure on the fuel rail also. The two parts when working properly should hold pressure in the fuel rail for weeks, and in perfect condition will hold for years. When one of the two go bad the system will have to be primed by doing exactly what you are doing. Either replace the parts or get used to priming the system, if I was in your situation I wouldn't worry much about it.

Thanks, thats an area I can look into.

Yes. Connect fuel pressure gauge turn the key on or run engine shut it off and wait to see if the pressure falls off. If so replace fuel pump module (assembly)

fuel pump check valve (ball) bad. Fuel pressure guage 58 with key on and then it drops like a rock. click key again it rises and then drops. Thanks for the help. For now I'll take the advice of priming, will change out pump alittle later though.

Check your battery. I had this exact problem on my 2002 and it was the battery. Mine was putting out only 10 volts so even though the pump was running the pressure was not good enough to start the engine. I had to do exactly what you described and it would start every time. Pull the battery cables off and check for 12 volts.

Potatoejay the battery wouldn't cause the fuel pressure to drop.

I know it doesn't seem right, but think of it this way. Dead battery, no pressure. It's physics really...less power to the pump = less pressure in the rails ( or delayed full pressure ). Just trying to help. This was the problem with my truck and I never would have looked at the battery.

And that would be an awesome answer and I would agree with it, IF he wasn't getting an initial Max pressure. The fact that he is getting full pressure and its dropping off means the pump is getting full power and creating full pressure but its not holding over night.

Yeah, you're absolutely right. I didn't see that he had max pressure initially and then it dropped. I'll bet you're right and he needs a fuel pump. It wouldn't be surprising in that vintage of truck. I replaced mine around 120K.

Fuel pressure regulator is also a possibility in these cases, the regulator is supposed to close when vacuum is removed. If the regulator sticks open it will bleed the pressure off also. Easiest way to check is to pull the fuel return line from the rail (as long as the connection is after the reg) get something to catch the fuel, and prime the system.

By following Mark helpful you will then also have to replace ign switch as it isn't designed to be operated in this manor. I'm afraid you will have to bite the bullet and replace the fuel pump as they don't have a fix for a bad ck valve.

It's been over a year and the ignition switch IS designed to turn.

My 2003 silverado 2500HD 6.0 is doing the same thing....I replaced the pressure regulator and it still does it.Will be looking on here for more answers before I pull the pump out of the tank .

I've replaced my -fuel pump -fuel filter -fuel pressure regualtor My 02'chevy 2500hd still has long crank times Any advice would be great!

I've also replaced my ignition switch. Really need advice that works!

Bad ignition coils or faulty fuel injectors

04 2500hd 6.0 doing the same thing. looking for help. I put a meter on the fuel pump pwr line and im getting 12v for 2 sec prime and 12v at ignition. But its intermittent, some times It works and other times I have to crank it 5-6 times before it gets fuel. Once it gets fuel it runs fine. Next step is to do a fuel pressure test off the fuel rails.

I have two chevy 2500's, both have had the same problem. First of all run the fuel gauge up in the cab and fuel pressure checked out fine. Tried a number of troubleshooting tactics. When it was all said and done I pulled the pump out of the tank and checked it. The problem was a small pin hole in the pick up line of the pump, which caused all the gas to drain out of the system when you cut the engine off. This is why your pump is having to run for a few seconds before cranking. Not sure if there were any recalls on any of the pumps. Just sounds like there is a manufacturer fault since I had two different trucks that done the same thing. However, you will never know until you pull the pump out of the tank and put it in a small bucket of gas to check it .

Ive replaced ever part imaginable.when i say every i mean every even the engine.$6000 later just learned to live with it its embarrassing .once it warms up it runs like a champ i put a high performance engine in my 2001 hd after replacing everything under the damm hood . IM happy with the engine but it still stalls when its cold once it warms up its fine

been through all of this i have no answer I replace almost every sensor, you name it even the engine and it still stalls.I put a high performance engine in my truck the engine runs awesome .but when its cold i just have to warm it up then its fine seem like it wasn't getting air so I put a K&N $300 filter on it sounds good but still stalls when its cold

I didnt know that first one went through sorry I have a 2001 Chevy 2500 hd 4x4 I only have a couple more parts to replace lol I replaced the MAF TWICE LOL im sick

I have a crazy question, have you replaced the torque converter? I have an old Plymouth that when ever the torque converter starts going bad, it stalls the engine when ever its cold. Once I finally get it to warm up, runs great.