2005 Tahoe/Fuel filling problem

[Tahoe97]

We are now having difficulty actually filling the fuel tank in our 05 Tahoe. The fuel nozzle from the gas station (any gas station) continues to kick off when we have it locked to fill, even on the slowest setting. Even if we manually hold the handle and try to fill after a gallon or so it kicks off, acting like the tank is filled which it clearly is not. Our local GMC dealership changed out the purge valve which after picking it up today did NOT solve the problem. We are also getting an error message on the dash telling us to tighten the fuel cap. This all started about 10 days ago and it now takes forever to fill the tank, 1-2 gallons at a time.

Does anyone have any idea about what might be going on with this?

Thanks,

JHE

 

[OR VietVet]

I am assuming you have not dropped the tank or done any other tank work recently, except for the purge valve, correct? That entire evap system needs diagnosed by a qualified shop and inspect the fuel fill tube/hose for a restriction. Time to get dirty.

 

[Bill 1960]

One thing to check is if the vent line is plugged with accumulated dirt. I’m not as certain on your generation but on mine it’s a recurring problem. The vent is behind the fuel fill and the rear tire slings mud up there which aggregates and blocks the vent. Then I get slow filling and codes.

That said, it’s quite likely to need some new parts. I have read a lot of stories from people who went about replacing parts without testing and ending up basically replacing the entire system. I second the advice from @PNW VietVet and get a qualified shop with a good scan tool to diagnose it properly. They can operate all the individual components and observe the system pressures to determine exactly which part is at fault.

 

[Tahoe97]

I am assuming you have not dropped the tank or done any other tank work recently, except for the purge valve, correct? That entire evap system needs diagnosed by a qualified shop and inspect the fuel fill tube/hose for a restriction. Time to get dirty.

Yes, the tank has not been dropped and no other work has been done.

 

[Tahoe97]

One thing to check is if the vent line is plugged with accumulated dirt. I’m not as certain on your generation but on mine it’s a recurring problem. The vent is behind the fuel fill and the rear tire slings mud up there which aggregates and blocks the vent. Then I get slow filling and codes.

That said, it’s quite likely to need some new parts. I have read a lot of stories from people who went about replacing parts without testing and ending up basically replacing the entire system. I second the advice from @PNW VietVet and get a qualified shop with a good scan tool to diagnose it properly. They can operate all the individual components and observe the system pressures to determine exactly which part is at fault.

To me this seems like the logical culprit. Is it easy to visually see this vent behind the fuel fill?

 

[Bill 1960]

It is on the GMT 900 07-14 models. It’s just zip tied to the fuel filler hose. I’m not certain on yours.

I just reach up behind the wheel and pull it down. Most of the dirt falls in my face, the rest I clean off and tie it back up. One of these days I’ll relocate mine.

 

[Fless]

Are you sure that it was the purge valve that was changed? It's on the engine. On the other end the vent valve vents the charcoal canister at times, and if it's stuck closed the tank can't vent as fuel is added. When the truck is turned off, the vent valve should be open; it's near the back of the fuel tank. Does your receipt show a part number for said replaced valve? (You likely do not have a vent valve that has been moved; that seems to be on later models.)

Other than that, overfilling the tank can compromise the charcoal canister, and the charcoal can get into the evap lines, blocking venting. I wouldn't base a diagnosis on that but it happens a lot.

You need a Tech 2 and evap knowledge, or a good shop (as @PNW VietVet noted) experienced with these simple systems.

 

[OR VietVet]

When I did my new fuel pump, during my build thread, I just went ahead and changed the entire evap system and used Genuine GM parts. That system can be a pain, as I have seen in many threads here, so I just said "to hell with it" and replaced it all with absolutely no problems.

 

[rockola1971]

When I did my new fuel pump, during my build thread, I just went ahead and changed the entire evap system and used Genuine GM parts. That system can be a pain, as I have seen in many threads here, so I just said "to hell with it" and replaced it all with absolutely no problems.

THIS. I believe the evap solenoid and vent filter assembly for evap runs around $20-30 and is a quick changeout too. Just gotta lay on your back unless you have access to a lift. Assembly is bolted to Drivers Side Frame Rail near the rear axle.

 

[Fless]

Vent valve location on my '04, at center rear of truck, in front of the spare tire. Pic is with fuel tank removed, vent valve in red square.