'94 GT won't take any fuel with an empty tank!?!

StreetPilot · Jan 22, 2016

Hoping someone has run into this issue and can help me figure it out. The other night I went to fuel up the car and it wouldn't take gas. Pump kept clicking off. Thought it was the pump so I went to another gas station. Same thing happens there- pump clicks off after about a second. If I try to fuel VERY slowly (about three pennies worth per second), I can get a little bit in at a time. Took five minutes to get three gallons into it.

It acts like the tank is full, but the gauge seems to be working and if I go slowly I can get gas in it, but it takes forever (pump handle keeps clicking off if I go other than uber-slow). My guess is that whatever allows the air to escape the tank when you put gas in is not working properly. Is this the EVAP system clogged up? Maybe a bad charcoal canister? I've never worked on that system on any of my SN's, so I don't even know where to start. I looked down the filler neck with a flashlight last night and there doesn't appear to be an obstruction, but I don't have a boroscope to see past the curve of the neck. Any help is really appreciated.

Jeff

P.S.- I have no idea why this post is so dark compared to others.

96blak54 · Jan 22, 2016

I had a ranger that did the same thing. Finally got it on the lift, pulled the neck of and the vent hose was loaded with dirt probably from a mud dobber. Cleaned it all out and work great. Pump fuel like normal

StreetPilot · Jan 22, 2016

96blak54 said:
I had a ranger that did the same thing. Finally got it on the lift, pulled the neck of and the vent hose was loaded with dirt probably from a mud dobber. Cleaned it all out and work great. Pump fuel like normal

That's a good thought. I wonder if some similar blockage could be the problem. Maybe there's a way ice could have formed on the vent and blocked it. It's been below freezing here for a week.

lwarrior1016 · Jan 24, 2016

If you jack the car up and take the rear passenger wheel off, you should be able to pull the vent line off the tank through there.

RichV · Jan 24, 2016

My 08 Expedition was doing the same thing.

It was the tank vent, it was clogged with a bunch of bugs. On that one, it went through the charcoal canister and some emissions stuff. Not sure how it's all plumbed in the SN, I haven't had any emissions stuff on it for a long time. I do know there is a hard plastic line, black IIRC, that runs from the passenger front fender into the engine compartment. That's the vent. Mine is just open to atmosphere.

ttocs · Jan 24, 2016

maybe with a small camera down the filler neck you could get an idea of what it was.

StreetPilot · Jan 24, 2016

lwarrior1016 said:
If you jack the car up and take the rear passenger wheel off, you should be able to pull the vent line off the tank through there.

I'll take a look that way. Maybe if the clog is up in the line running to the canister, simply taking it off the vent will allow air to escape freely and I can at least get fuel in it. If I can get that far, finding the clog will be the next target. Thanks!

RichV said:
My 08 Expedition was doing the same thing.

It was the tank vent, it was clogged with a bunch of bugs. On that one, it went through the charcoal canister and some emissions stuff. Not sure how it's all plumbed in the SN, I haven't had any emissions stuff on it for a long time. I do know there is a hard plastic line, black IIRC, that runs from the passenger front fender into the engine compartment. That's the vent. Mine is just open to atmosphere.

I stopped by the stealership yesterday and had them print out an EVAP system diagram, and it shows just what you're talking about in the engine bay. I'm going to check that out in the morning. I might just be something pinching the vent line or something similarly simple.

ttocs said:
maybe with a small camera down the filler neck you could get an idea of what it was.

I wish I had one. I'm going to ask a few friends and see if someone has one. Great idea.

StreetPilot · Jan 26, 2016

PROGRESS!!!!

OK, so here's a little update:
Last night I had a few hours so I decided to start figuring this thing out. I pulled the hose off the vent line and drove to the gas station. Car took gas normally, so at least I know a few things: I can now fuel the car normally, the filler neck is clear, the tank vent works, and that the problem is downstream. I followed the vent line along the fuel lines to the front of the car and it seems fine. No pinch or crushed areas, so that's good. I took of the pass. front wheel and fender liner to get a look at the canister. When I got there, I looked at all of the lines and the one that goes to the back of the intake looks to be in VERY rough shape due to being 22 years old. I followed it out of the fender and up behind the intake, and it was then that I realized that this is the same vent line that I was messing with about a month ago.

During an oil change last month, I accidentally pressed down on the little canister that looks like a "D" sized battery (I forget the name of it) with a hose attached to the top of one side and another attached to the other side that goes to the back of the intake. I had to replace this little canister because the nipple broke off of one side (extremely brittle due to age). Now some of the nipple pieces were still in the hose and hard to remove so I used a pair of needlenose pliers to remove the pieces before I installed the new canister. My guess is that one of the little broken pieces was too far in for me to spot and has now become an obstruction that is blocking the vent line, causing my inability to fuel normally. I'm going to test this theory tomorrow by taking the vent hose off of both sides of the canister (one at a time, of course) to see if I can fuel with it off. If I can fuel with the side that goes to the charcoal canister off, I'll know that it's either the little canister itself gone bad (or blocked internally due to some of the plastic debris), or that the blockage is on the intake side further down. If I can fuel with the line off the intake side of the little canister, I'll know that it's blocked on that side either somewhere inside the vent line before the intake or inside the intake. If that's the case, I'll just replace that vent line. As long as the broken piece didn't get into the intake, I should be good to go.

This is all conjecture on my part, but the theory is sound. If the blockage isn't there, I'm likely dealing with replacing the charcoal canister and associated lines, of which there are several. Wish me luck!

evilcw311 · Jan 26, 2016

Or you could just eliminate the hose back close to the tank and let it vent to atmosphere as lots of people do.

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Addermk2 · Jan 28, 2016

You need a canister.

End of thread

GregT94SCC · Jan 31, 2016

Sounds like you need a mityvac. Great too for testing lines, solenoids among other things. No point throwing parts at it until you correctly identify the problem.

StreetPilot · Feb 1, 2016

Addermk2 said:
You need a canister.

End of thread

Maybe. I tried to do some further troubleshooting while fueling last night. I took the hose off the little inline "D"-sized battery looking valve under the hood, and it fueled fine. I put it back on and then if fueled fine too (everything installed and hooked up, so stock condition), so now I've got a system that was having a problem, didn't get to troubleshoot it thoroughly, and now the system is working normally

. I had a hard time getting the line off of the little battery looking valve, and could potentially have knocked a blockage loose and cleared it accidentally. I may never know, but it's working now so I'm going to let it ride.

evilcw311 said:
Or you could just eliminate the hose back close to the tank and let it vent to atmosphere as lots of people do.

Do you get fumes in the garage if you do this? If not, I think nice little filter on the end of that line (to keep out debris and bugs) is just what the doctor ordered.

evilcw311 · Feb 1, 2016

If you can fix it easily and cheap enough then adder is correct, fix it.

But if it seems to be like a complete pain or not cheap and easy then yes, you can just put a small filter in back and honestly I've never had an issue with fumes.

Others who have done this can probably chime in and say if they've ever noticed fumes from theirs.

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Addermk2 · Feb 1, 2016

I removed mine, but I also left the line that ran to it. its still open behind the front fender.

I also leave my cap loose. I pump so much fuel volume that my ORV cant keep up. My tank actually started to cave in...

evilcw311 · Feb 1, 2016

^ this is how mine is done as well.

When I replace my tank and pumps I'll probably go ahead and remove all of the line when I run my new fuel lines.

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StreetPilot · Feb 7, 2016

Thanks for all of the ideas guys. Whatever the blockage was either was freed up by my trying to check the inline valve, or if it was ice it melted away when the weather warmed up over the last week. I've refueled twice now after messing with it and haven't had any problems fueling with everything hooked up. Wish I knew the cause though.