Can't fill tank after shortening

skumancer · 09-03-2022, 11:36 PM

Shortened the gas tank (5.4L V8) in April, and have been converting my van to 4x4 ever since. Last month after finishing the conversion, I tried filling the tank and it would not fill easily, had to do it little by little.

I dropped the tank today to see if there was anything weird going on, but everything checked out AFAIK.

The only other answer is something to do with the EVAP system/charcoal canister, but I have NO codes coming up. Any clues on where to go from here? I don't want to spend $150-$250 on a canister just to find out it was not the problem...

**BroncoHauler** · 09-04-2022, 08:30 AM

Did you change anything with regards to the tank vent line?

Herb

marret · 09-04-2022, 08:36 AM

If not the vent, sure the fill tube/hose is unobstructed?

deserteagle56 · 09-04-2022, 10:28 AM

Either a kinked/obstructed fill line or vent line. Something is causing back pressure to make the nozzle pop off.

In my case the outlet to the evap canister was plugged with mud. But I never had any codes come up - just a problem with the fuel nozzle popping off when I fueled.

skumancer · 09-04-2022, 10:48 AM

Quote:

Originally Posted by BroncoHauler

Did you change anything with regards to the tank vent line?

Herb

Nothing. Just shortened the tank before the front breather. I used compressed air to check that the breather lines and holes were clear, and they are.

skumancer · 09-04-2022, 10:50 AM

Quote:

Originally Posted by deserteagle56

Either a kinked/obstructed fill line or vent line. Something is causing back pressure to make the nozzle pop off.

In my case the outlet to the evap canister was plugged with mud. But I never had any codes come up - just a problem with the fuel nozzle popping off when I fueled.

Interesting...so just a kink on the fill line can cause this? I'd say mine is not perfectly smooth.

DC22 · 09-08-2022, 12:32 PM

Did you re-coat the interior of the tank with a tank liner after shortening it? When I did mine, the rollover valve insider the filler spout got “glued” shut. I had to knock it loose with a rod and hammer. Worked fine after that.

SteelheadJones · 09-08-2022, 11:06 PM

Took me a while to remember whose thread had a similar problem. Check out the last pic in post #37 here.

skumancer · 09-25-2022, 10:20 PM

Thanks for all your input. I finally found what the problem was.

After suffering through a trip with 5 tank fillings taking more than 30 minutes each, I bought a replacment Fuel Vapour Valve (Part#:4C2Z9189AB) which goes on the filler neck and two Fuel Vapour Valves (Part#:4C2Z9B593AB) which go on top of the tank and connect to the EVAP system.

While replacing the three items, I noticed the Vapour Valve on the filler neck was in the rubber hose and not attached to the tank inlet itself, which I believe was the real cause of my troubles.

I replace all 3 valves and was able to fill out the tank without a hitch.