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I can no longer fill up my gas tank in one go. This started gradually over a few months, initially only happening at one pump at the closest station.

Now, however, I can't get more than a gallon or so before the pump clicks off. I then have to pull the pump out, wait a few seconds, after which I can put in another 3/4 of a gallon or so.

I've looked at other posts which all indicate a bad EVAP solenoid, or blocked vapor line from the tank to the filler neck. I recently replaced the solenoid. For kicks, I went ahead and pulled it off and I can blow through it easily.

I removed the trunk liner and blew compressed air through the vapor line with the gas cap removed. I can feel the air - lots of it - coming out where the gas cap goes. I also blew out the line going to the solenoid and can feel the air coming out there as well. So, no indication of a blockage.

Occasionally, I get a "Check gas cap" message on the DIC, though the cap is secured. I also replaced the cap - no effect. The message is intermittent and shows up every 2-3 weeks, and always disappears fairly quickly.

Suggestions? Where to next?

Also, I've just discovered that the oil change idiots overfilled the engine by about 3 quarts (capacity is about 5). Not sure if that would cause this - seems unlikely.

UPDATE

Removing the CAN fuse didn't have any effect. However, I disconnected one of the vapor lines above the gas tank, and was able to fill it up in one go. This is one of the lines I cleared with the air compressor, so I'm guessing the obstruction is on the other side - in that big array of ominous black boxes.

I'll check the canister outlet for spiders later, but at least this is progress (as in, I no longer feel like a redneck who has never had a full tank of gas). (I'm from Oklahoma - i'm allowed to say "redneck.")

Here's the line I disconnected:

Disconnected vapor line

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  • 1
    Is this for the Solstice?
    – Pᴀᴜʟsᴛᴇʀ2 ♦
    Dec 14, 2016 at 21:36
  • @Paulster2 Yes. Sigh. I hate this car.
    – 3Dave
    Dec 14, 2016 at 21:36
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    It's too awesome of a car for you to hate it ... my suggestion? Get the LSx/T56 swap ready for it :o) Put a fuel cell in for good measure and call it a day.
    – Pᴀᴜʟsᴛᴇʀ2 ♦
    Dec 14, 2016 at 21:37
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    @Pᴀᴜʟsᴛᴇʀ2 I actually have an LS1 sitting in the shop. Still looking for a good deal on a transmission. Have to have a driveshaft fabricated, make some motor mounts, etc. Big project. Need to fix my G35 so I have something to drive first.
    – 3Dave
    Dec 14, 2016 at 21:38
  • Which EVAP solenoid did you check? The Vent (under car)? Or the Purge (engine)? Try disconnecting the line from the charcoal canister to vent solenoid.or if you have a pressure regulator pull the schrader valve out of the evap check port and put 1 psi into the system, watch your fuel tank pressure voltage and ground the evap vent solenoid KOEO.
    – Ben
    Dec 15, 2016 at 0:48

1 Answer 1

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Slow or no flow for fuel in means no or low vapor flow out the vent system. Steps to test for testing for a blocked vent:

  1. Remove the CAN VENT fuse, #64 in the Underhood Bussed Electrical Center (UBEC).

  2. Recheck fuel fill.

  3. If now OK, check the White evaporative vent solenoid wire for a short to ground, between the evaporative vent solenoid on top of the fuel tank to the Electronic Control Module (ECM), pin 55.

  4. If removing the fuse is no help, drop the fuel tank down, check the evaporative vent solenoid, evaporative canister, evaporative vent hose for restriction such as a kink or dirt or spiders.

We pulled several live spiders from a vent tube recently.

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  • It's been freezing here in DFW. I'll give all of this a shot when my teeth stop chattering.
    – 3Dave
    Dec 19, 2016 at 21:40
  • See my update. Removing the fuse didn't help, but disconnecting the vapor line above the tank did.
    – 3Dave
    Dec 22, 2016 at 20:53

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