Thread: Gas Tank Hard to Fill

I have an 04 Grand Prix (not supercharged). I bought it and let it sit for about 6 months. Now the tank is hard to fill--the pump keeps shutting off. I asked a GM dealer about it. I thought it may have a roll over valve in the filler neck. The dealer said it does not but does have a purge valve that is probably stuck on top of the tank. Apparently it vents to the intake. Has anyone experienced this? I don't want to drop the tank without some confirmation that is the problem. I really don't know what else would cause pressure in the tank to keep kicking the gas pump off though.

Thanks.

Originally Posted by E IN v Y

Are you getting any codes?
You should check the vent soleniod. Check to see if its clogged.
Its located in the rear left side. You may have to take off the wheel and cover, its a small hose.

P0446 which does not tell me much. Vent solenoid differ from the purge valve? Can anyone confirm there is a purge valve on top of the tank? (chevy dealer told me that).

I disconnected the tube near the filler neck that connects to a canister. There is also a sensor on the canister. No difference with the tube disconnected. There must be another cause than a clogged canister.

Originally Posted by jeffconnors

P0446 which does not tell me much. Vent solenoid differ from the purge valve? Can anyone confirm there is a purge valve on top of the tank? (chevy dealer told me that).

I disconnected the tube near the filler neck that connects to a canister. There is also a sensor on the canister. No difference with the tube disconnected. There must be another cause than a clogged canister.

My car is having the same issue. The shop told me (a long time ago) it could be the pressure sensor on the gas pump but I don't think that is it.

EVAP system in stock form has....The EVAP purge at the front in the engine bay, charcoal canister on the driver side rear behind the tire under the body of the car. There is a sensor connected to the charcoal canister that opens and shuts the purge for the canister. Right now I don't have the front I cut that off and put a little filter on it. I plan on removing the charcoal canister and seeing if I can just spice the two lines together.

Good info ---thanks.

Originally Posted by Pure2sin

There is a sensor connected to the charcoal canister that opens and shuts the purge for the canister. Right now I don't have the front I cut that off and put a little filter on it. I plan on removing the charcoal canister and seeing if I can just spice the two lines together.

That is the same thing I am talking about. There is the canister then the actual sensor (solenoid) the activates the purge. From what I have read you can unplug the sensor so that it will remain open at all times and should cure the problem, although it will set a code if you don't tune it out.

Originally Posted by Pure2sin

That is the same thing I am talking about. There is the canister then the actual sensor (solenoid) the activates the purge. From what I have read you can unplug the sensor so that it will remain open at all times and should cure the problem, although it will set a code if you don't tune it out.

tried upplugging the sensor. Did not work. I don' t want to drop the tank unless I know with reasonable certainty that the purge valve on top of the tank is bad.

Originally Posted by Pure2sin

What one did you unplug? The one in the engine bay or the one behind the rear driver side quarter panel by the gas filler neck?

By the gas filler neck.

Originally Posted by jeffconnors

By the gas filler neck.

That's a tough one then. I also thought that some years have a vent line connected to the filler neck that can get clogged or rusted.

The only other thing could be that the EVAP line and/or canister is clogged also but I would think that would throw a code.

I just picked up an 04 last weekend. It is horrible to fuel up. It is so bad I cant even get it to flow constant at the slowest rate while holding the pump handle and it still clicks off. If anyone came to a solution, please post. It is going to be very cold here soon!