2005 GMC 6.0 fuel pressure regulator?

Where is it located? Truck was hard to start so I changed the fuel pump. Still acting up when warmed up. Friend told me to look at regulator but it is not where it was on his 5.7 liter. Help?

Might be in the pump module.  Pretty sure that's a returnless system.

Pulled the bed and replaced the unit inside the tank,ame problem 

Fuel filter, maybe? Cheap enough, easy enough, since you've got the parts cannon out. 

any codes?

In reply to dean1484 :

Couldn't hook up my cheap code reader

In reply to RealMiniNoMore :

Fuel filter was non-serviceable item couldn't buy one at the parts store? With the unit in the tank?

I would see about getting a loner fuel pressure gage set from the parts store and see what the pressures actually are. 

dean1484 said:

I would see about getting a loner fuel pressure gage set from the parts store and see what the pressures actually are. 

Absolutely this. Find out what the pressure specs are and see what you actually have. But if you have two lines attached to your fuel rail then the regulator should be at your fuel rail. It will have a vacuum line hooked to it. And im pretty sure that truck should have a serviceable fuel filter.

In reply to TRoglodyte :

Rock Auto lists one. Fuel filter

Now I feel like an idiot, assumed parts man was right and never verified myself, saga will continue when i get home.thanksfor the input.

Don't feel bad, man. Parts stores don't always stock /carry everything, like The Rock does. 

It is a fuel injector pressure regulator.  It is up on the rail on top of the motor.  If the parts guy was searching for just a fuel pressure regulator (and did not have the word injector in there) he/she would probably come up with nothing.  

From your description I would check the actual pressures.  I would not rule out the sensors that tell the ecu that the motor is actually spinning. of I think there is a sensor in the tank that tells the ecu the fuel pressure in at/in the tank.  I also hate to say it but you could have a bad pump of something is leaking in the tank on the pump unit that is allowing fuel to drain back from the rail to the tank.  I think there is a check valve that is there to prevent this. You could also have bad injectors that are leaking.  

Is it hard starting all the time or just after sitting over night?  

Starts and runs fine when cold, drive 30 miles and it is hard to restart.

There are an awful lot of bad in the box new fuel pumps being sold today. Spectra & Airtex in particular, but not limited to those brands, which are the only ones available now for some mi'90s Fords

In reply to TurnerX19 :

Yeah I bought a fuel pump from a reputable supply house and it's acting the same way as the other one did. I looked under the truck last night and can't find a fuel filter by the frame rails or a fuel pressure regulator. The gas lines run directly from the tank to the injector rails.

Do you borrow a fuel pressure gauge at FLAPS? Are they generic? One size fits all?

The symptom sounds like a lack of rest pressure. Make sure the system retains pressure for 20 minutes after shut down. If this vehicle triggers the pump briefly before you crank it, try cycling the key on/off several times before you crank it the next time it miss-behaves. If it then starts OK it confirms lack of rest pressure. This trick does not work on systems that do not do a pump run prime cycle though.

In reply to TRoglodyte :

I would ask them.  There should be a fitting on the rail.  It may be GM specific but a decent pressure gage kit should have adaptors for that as well as other brands

Is it possible that the filter and regulator are both on the fuel pump unit in the tank? I have chased the lines from tank to injector rails and cant find either one where they are on my 2000 model 5.3 liter truck. This truck is a 2005 GMC Sierra Denali. Google isn't offering much help and I am bumfuzzled. Will try to get a gauge tomorrow .

In reply to TurnerX19 :

Got a heads up on the Airtex from a friend,May have to add Precision to that list. Truck starts well when cold so I dont think it is the check valve, that is why I am hunting the regulator.If all three are in the pumping unit under the bed that suxx.

In reply to TRoglodyte :

Check valve affects hot start far more than cold start on any system I have worked on. Those are mostly old ones, but it was a common failure for a long time. Currently I am struggling with a Ford, and I think we are going to add a Bosch "044" of the race car variety after the new in tank Spectra on a certain work truck I must maintain.

Got a fuel pressure gauge at the loaner tool and it's holding 50 pounds when I turn the key on and 50 pounds when running. The parts store has a fuel pressure regulator listed and showed me a picture of it but I can't find its physical location on the truck.. Any input would be greatly appreciated

Up on the fuel rail.  I have an 03 wth the 6.0 in it I think it is the same.  If you have the plastic cover thing on the top of the motor still that has to come off to see it.

In reply to dean1484 :

I have pulled the plastic covers off and Chased the fuel line and fuel rails from one end to the other and cannot find a part I saw at the parts store. Engine is at operating temperature now and won't build over 30 lb of pressure on the gauge.