2001 2500HD Hard To start

I have a 2001 2500HD 6.0 that when the truck sits for an hour or so and you try to start it it will just keep cranking,but when you stop and then turn the key to crank it again it starts right up..Any ideas? I was thinking maybe the fuel pressure regulator or the fuel pump.

You got it, either FPR or fuel pump. I had the same problem on my 02 4.8. I replaced the fuel filter and FPR, but did not fix problem. Replaced pump, and problem fixed.

Check your FPR by running the truck for a while then shutting it down and pulling the vacuum line on the FPR. If fuel runs out it needs to be replaced.

A fuel pressure test should also tell you what the problem is.

Replace the fuel filter if you havn't done so in a while.

Another possibility is a plugged fuel filter, happened on a 2001 Suburban 5.3 that I worked on once.

I had a problem with my truck where sometimes it would crank fine, others it would keep turning and turning and eventually crank. Everything was fine that I could tell. It wasn't a major issue until I was driving 80 down the interstate at night and everything shutdown. After a couple trips to the mechanics it ended up being a faulty crank sensor located back behind the engine, so if your problem persists it could be something to look into.

I had a problem with my truck where sometimes it would crank fine, others it would keep turning and turning and eventually crank. Everything was fine that I could tell. It wasn't a major issue until I was driving 80 down the interstate at night and everything shutdown. After a couple trips to the mechanics it ended up being a faulty crank sensor located back behind the engine, so if your problem persists it could be something to look into.

Was that on the 8.1? That is a common problem on those engines.

Sounds like fuel pump and stay away from aftermarket fuel pumps,they are junk.Airtex and Carter are two to stay away from.Most aftermarket fuel pump's warranties are deneied right away.Go with a GM fuel pump from the dealer.Went through this last month,put 4 fuel pumps in my cousin Steve's 2001 Olds Alero.Three were Carters and the 4th one one is a GM fuel pump.Have not seen it since after puttting in the GM pump.

Was that on the 8.1? That is a common problem on those engines.


Yes. It was with the 8.1L, now I have some type of problem with a loose shifter causing the key to not turn.

Thanks for all the good advice I've been working alot lately and now just getting the time too look into it. I think I will try the FPR first because it's a little cheaper and easier to replace. Thanks!! I'll let you guys know if that works.

Yeah I would try everything before replacing the pump. It is a pain in the ass, and expensive. Do a fuel pressure test on it and post back the results:

You fuel pressure is to low.
Specs on it is 55/62 lbs of pressure
Here is some guide lines of fuel pressure checking.

Hard to start cold.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
Later V6 and V8 gm engines should have 55-66 fuel pressure.
Cold start should be 55/62 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Engine running should be 55/62 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak.
If pressure does not come up with return line pinched or blocked off.
Go to fuel filter and hook a gauge direct to a line at fuel filter.
Pressure should come up to 75 or more and will hold after fuel pump is turned off.
If it leaks down there after fuel pump is turned off it is LEAKING BACK THREW PUMP CHECK VALVE OR PUMP MODULE LINES.
Post back your fuel pressure readings.
(Copied from MT)

Now when I start the truck and it finally starts after having trouble starting it runs rough and it gives the code multiple missfire. I turn it off and restart it, it will start up perfect and run perfect and run fine after that until I let it set for awhile. It doesnt do it everytime but more often than I would like. Also I took it to the dealer and they said I had clogged injectors so I had them do the recomended injector clean, But that did not help.Thanks.

The dealer said they also checked the fuel pressure and it was within spec,But I forgot to ask them what there spec was.

Whose fuel ya buyin?

Since I work for Valero I also buy their gas. But i'm more inclined to say it is the fuel pump. I'm going to do the fuel pressure check myself

Valero? Wouldn't you be better off running water with starter fluid? Yuck.

Valero? Wouldn't you be better off running water with starter fluid? Yuck.
I can tell you no nothing about the refining of gasoline.

I can tell you no nothing about the refining of gasoline.

wasnt Valero in the top five tier of gasoline? I know exxon WAS NOT and for some reason I still use it :(

You're correct. I don't refine oil for a living. However, I do KNOW (correct spelling there for ya.) what comes out the nozzle at the pump. And Valero is crap. That is not my fault, nor my problem. I made the misfortune of attempting a lil humor to point out the gas you're using is right in there with pissing in a gas can, but I guess I needed to break it down purple dinosaur style for you. My apologies and good day. Good luck with your truck.

Truth be told all the refining companys buy and sell each others products. As far as the blends needed to produce gasoline. (i.e toluene,xylene,etc.) Sometimes if your local Exxon,Citgo or whatever gas company runs low on fuel at the pump they will buy fuel from one of the other gas companys to meet the supply. So what that means is if I go to my local Valero and the truck rack was down or supply was low and they couldnt have fuel delivered, I could be filling my tank with gas they had to buy from say Citgo in order for them to meet demand. I hope that doesnt confuse anybody.

Thanks for all the advice!! I got my truck fixed yesterday and it was the fuel pump. It runs great now Thanks!!!!!!