04 Denali, long cranking before starting

[Rocket Man]

I've never heard of the FPR being on the pump module, but I've never had a reason to look into that, either.

They moved them to the fuel pump module in 03 or 04, can't remember. Just to make things more difficult.

 

[iamdub]

Ooooooof course they did.

 

[asand]

Could be one or more leaking injectors. Pintle leaking pressure into the intake manifold causing a really rich mix on one cylinder and leaving no pressure in the lines overnight. Try keying it on and off a few times to prime the system before starting.

 

[willinnashville]

Keep us posted on what you did to fix it please

 

[latvius]

I recently had a similar issue in my 05 Tahoe, bought a $40 HF fuel pressure gauge and found the return check valve was stuck open. Once you turn the key the fuel pressure comes up and after the pump stops it drops just as fast. Check valve is on the fuel pump so ended up replacing fuel pump. Starts first time every time now and fuel pressure stays up after pumps stops when you turn the key.

 

[mhorn0817]

Symptoms point to fpr, fp, or the cv...but the strong gas smell doesnt
There are no visible leaks and i cant smell so im relying on others to tell me where the smell is coming from, in which they say front and back so who knows

 

[latvius]

Now that I think about it I used to get a fuel smell every once in a while, never found the problem but have not had it since replacing the FP. I don't have an explanation of why it was there and why it is gone but if you get a FP reading it will help you get some more clues for diagnosis.

 

[mhorn0817]

Fuel smell started before the starting issue. Smell is bad enough to where people just walking by can smell how bad it is

 

[latvius]

Well you have two known symptoms, a gas smell and it takes longer than normal to start. Could be the same problem, could be two different problems. Fuel smell is when gas is exposed to air so you might be able to see visible signs of leak. If you don't I'd move on to the hard start problem check it with FP gauge and go from there. Maybe when you fix the hard start problem the gas smell goes away or maybe it makes it easier to identify.

That's how I would approach the problem.

 

[iamdub]

You may have an external leak, like a line or connection somewhere from the bulkhead on top of the tank to the many fittings on the EVAP stuff and on up to the fuel rail. After it has sat for a while, turn the key on for about 5 seconds to pressurize the system, then turn it off for about 5 seconds. Repeat this a few times then look and sniff around underneath for any wetness.