Fuel Tank Vent Line
Discussion
I suspect my vent hose has become blocked as I can't add fuel without it bubbling back out of the tank. I want to blow out the line but I'm not sure how to get to the hose.
At the neck end, it looks like the the side panel that holds the light and speaker should come off if the two screws (one above the speaker and one just below the parcel shelf) are removed. But it doesn't budge and I don't want to force it. Are there more screws or a trick?
Where does the tank end meet connect to the tank? I had a quick look while working on the brakes and didn't see where if connected. Is it connected to the tank near the filler neck or the far tank?
At the neck end, it looks like the the side panel that holds the light and speaker should come off if the two screws (one above the speaker and one just below the parcel shelf) are removed. But it doesn't budge and I don't want to force it. Are there more screws or a trick?
Where does the tank end meet connect to the tank? I had a quick look while working on the brakes and didn't see where if connected. Is it connected to the tank near the filler neck or the far tank?
Hi Grady
The trim should just have two screws holding it in place...There might be another though where it extends down between the seat and body shell...But should come off...Try carefully prising the light out and disconnecting the wires as sometime they can be fairly short in length and hinder the removal.
The breather is connected to the filler neck and runs up inside against the boot firewall and then down to the left rear wheel arch.
Hope this helps.
Ziga
The trim should just have two screws holding it in place...There might be another though where it extends down between the seat and body shell...But should come off...Try carefully prising the light out and disconnecting the wires as sometime they can be fairly short in length and hinder the removal.
The breather is connected to the filler neck and runs up inside against the boot firewall and then down to the left rear wheel arch.
Hope this helps.
Ziga
I can't see how the vent pipe would be causing your problem because it is just inside the filler tube and smaller than the gap around the pump nozzle so any displaced air would take the larger opening to escape. Are you using the same filling station? Maybe the problem is the pump nozzle?
As Zigga says, the big side trim panel is held to the 'B' post by a screw concealed by the 'B' post trim panel. Here's a picture of how it is secured.
It's very unlikely you will have the ply packer.
Beyond this screw there could be any combination of other screws holding the large panel in place so just wiggle carefully to see where these might be. Be very careful if one of the screws looks like it might be close to the side glass.
As Zigga says, the big side trim panel is held to the 'B' post by a screw concealed by the 'B' post trim panel. Here's a picture of how it is secured.
It's very unlikely you will have the ply packer.
Beyond this screw there could be any combination of other screws holding the large panel in place so just wiggle carefully to see where these might be. Be very careful if one of the screws looks like it might be close to the side glass.
Thanks - I'll look for the 3rd screw.
The overflowing is a "new" problem. However, the car sat-up for 3 years before I replaced the clutch and I've been adding sips of gas as I have been getting it back on the road. A couple of weeks ago I added 4 gallons which "disappeared" (but not on the driveway). The 4 gallons went right down the neck with no problems. Now the tanks are empty and very nearly empty. I thumped them when I was underneath working on the brakes but don't remember which one was completely tinny/empty.
I tried adding fuel from a can and a pump. Same thing: After less than a 1/2 gallon, the filler neck was full up to the flapper valve which is 3-4 inches down the filler neck (which cut off the pump). I stopped adding more fuel but fuel (in the 'empty' tanks) expanded up the neck until it over-flowed down the side of the car. I slammed the cap back on which stopped the over-flow. After a wait, I could repeat the exercise.
The car was on a level drive and turned off. The fuel (in the can anyway) was ambient and the outside temperate was normal. I'd say that rules out the car's fuel pump doing something weird as well as some massive fuel expansion. And with the tanks being empty, it wasn't just an overflow.
I experienced a similar problem with EVAP system on my other car. The fuel backed up in the neck and cut off the pump unless you trickled it in (fill-up took 20+ minutes). Having replaced the charcoal canister, purge valve and solenoid (that's pretty much everything to replace) with no improvement, I blew out all the lines with 100 PSI of air and that seemed to resolve the problem.
I'm going to (carefully) run a wire/rod down the neck and confirm that there isn't a physical jam - dead mouse - in the filler tube and try blowing the lines to see if any of that helps.
On a more positive note, after standing in line for an hour, I got my registrations renewed - fully street legal again!
The overflowing is a "new" problem. However, the car sat-up for 3 years before I replaced the clutch and I've been adding sips of gas as I have been getting it back on the road. A couple of weeks ago I added 4 gallons which "disappeared" (but not on the driveway). The 4 gallons went right down the neck with no problems. Now the tanks are empty and very nearly empty. I thumped them when I was underneath working on the brakes but don't remember which one was completely tinny/empty.
I tried adding fuel from a can and a pump. Same thing: After less than a 1/2 gallon, the filler neck was full up to the flapper valve which is 3-4 inches down the filler neck (which cut off the pump). I stopped adding more fuel but fuel (in the 'empty' tanks) expanded up the neck until it over-flowed down the side of the car. I slammed the cap back on which stopped the over-flow. After a wait, I could repeat the exercise.
The car was on a level drive and turned off. The fuel (in the can anyway) was ambient and the outside temperate was normal. I'd say that rules out the car's fuel pump doing something weird as well as some massive fuel expansion. And with the tanks being empty, it wasn't just an overflow.
I experienced a similar problem with EVAP system on my other car. The fuel backed up in the neck and cut off the pump unless you trickled it in (fill-up took 20+ minutes). Having replaced the charcoal canister, purge valve and solenoid (that's pretty much everything to replace) with no improvement, I blew out all the lines with 100 PSI of air and that seemed to resolve the problem.
I'm going to (carefully) run a wire/rod down the neck and confirm that there isn't a physical jam - dead mouse - in the filler tube and try blowing the lines to see if any of that helps.
On a more positive note, after standing in line for an hour, I got my registrations renewed - fully street legal again!
mmmm...or how determined they are...Its possible that it could be evaporating off due to a hole in the tank or hose...You don't always see it on the floor unless you put some hardboard or cardboard down...Fuel will leave a stain on absorbent mediums....
The only other thing I can think of is that the car has a mind of its own and it a fuelcoholic...
The only other thing I can think of is that the car has a mind of its own and it a fuelcoholic...
Hey guys, your all talking about the in lines and vent but what about the out Lin out lines.
A few years back the lines coming from the tanks to the swirl pot to the fuel pump on my 280 disintegrated from The inside out filling the fuel pump and the inside of the lines with rubber goo.
If gas can't get out it would act full which it might be.
My lines were all original. Just being the 👹With an idea. DRAIn the tanks and see what and how much comes out.
A few years back the lines coming from the tanks to the swirl pot to the fuel pump on my 280 disintegrated from The inside out filling the fuel pump and the inside of the lines with rubber goo.
If gas can't get out it would act full which it might be.
My lines were all original. Just being the 👹With an idea. DRAIn the tanks and see what and how much comes out.
Update - I got the side panel off (missed an now obvious screw). Got the two side hoses off and blew them. I sounded the tank with a stiff wire. Hissing back through the neck on the small one and fuel splashing out of the neck on the bigger one. Best I can tell, the tank next to the filler is actually full. Sure thumps like it's empty, So that would explain where my 4 gallons went and why it bubbles out. No idea what is happening with the far tank.
Looks like I may have another problem with the car acting like it has run dry on starting. Went out and made two stops. After the first stop, it started on the first turnover. 2nd time I had to wait a couple minutes. Suspect it's an undefined fuel issue.
I also played with the fuel sender. The gauge moves from over-full (when I cross it with a jumper) to under-empty (wires disconnect from the sender). Across the sender (indicating a 1/3rd tank) is reading 0.094 ohms (meter set to 2K scale). Any idea what the resistance should read?
Anyway, it looks like a new sender will be needed. Any ideas the parts number or values for a fuel sender for a VDO? I see some on eBay but don't know if they would be compatible. Didn't see anything on the parts sticky.
Looks like I may have another problem with the car acting like it has run dry on starting. Went out and made two stops. After the first stop, it started on the first turnover. 2nd time I had to wait a couple minutes. Suspect it's an undefined fuel issue.
I also played with the fuel sender. The gauge moves from over-full (when I cross it with a jumper) to under-empty (wires disconnect from the sender). Across the sender (indicating a 1/3rd tank) is reading 0.094 ohms (meter set to 2K scale). Any idea what the resistance should read?
Anyway, it looks like a new sender will be needed. Any ideas the parts number or values for a fuel sender for a VDO? I see some on eBay but don't know if they would be compatible. Didn't see anything on the parts sticky.
Edited by Grady on Tuesday 25th April 23:07
Edited by Grady on Wednesday 26th April 01:05
Time to get the connecting pipes off between the tanks? If you had a blockage in the bottom connecting/take off pipe this may explain what you are seeing... O/S tank is not using fuel so splashes out when you try to fill up. Some petrol will get to N/S tank, but possibly not enough? Petrol only being used N/S tank so doesn't have much range? Not sure what the sender is reading but I think it's installed in the O/S tank so if the petrol in this tank isn't being used it may give a false idea of what's going on. Cheers Steve
SEvans said:
....Time to get the connecting pipes off between the tanks? .....
Without a ramp that is a right bas
rd of a job so try and check all other options first. If you do end up having to do this, you'll need 51mm ID fuel proof pipe which is expensive. It may be possible to cut off the old pipes and put the new ones on by sliding each one fully onto one side then pulling it back onto the other. You may have to slacken off the tanks to get a bit of extra space, but maybe not, depends on how lucky you are. You might as well replace the short pieces on the connector tube at the bottom and the vent/return pipes as well while you're at it. You'll only want to do this job once! Get in lots of Vaseline, plasters and tea bags/coffee 
At least you'll be doing it in warm weather. I did this job last November with the car cover spread out like a tent to try and keep the rain off. At least it was dry under the car
Grady said:
Looks like I may have another problem with the car acting like it has run dry on starting. Went out and made two stops. After the first stop, it started on the first turnover. 2nd time I had to wait a couple minutes. Suspect it's an undefined fuel issue.
Sounds like a faulty accumulator..If yours has a breather pipe on the back then clamp the hose from the accumulator to the metering unit and loosen the breather hose..Crank or prime the pump...Do not start the engine...It only needs to be a couple of seconds of priming ...If any fuel comes out of the breather then the diaphragm is shot..You can quite happily run the car without one but will need a 1/4 on the gas to aid starting...Cant see it being a blocked pipe...I wouldn't rule it out but more investigation is needed.
It would have to be a bloody big mouse to block a 51mm ID hose...Unless its full of fuel of course...
If you do need to change this then you can buy fuel delivery hose or aircraft hose but avoid the steel helix type like the plague...Trust me on that one!!!....
Ziga
Grady,
Instead of ramps you may want to go to your local Harbour Freight and buy the aluminium motorcycle/ATV jack; it only has a 1500 lb capacity, but that is enough to lift the rear to about 19". It is a beautifully made piece of equipment and I'm sure you can find a 20% off coupon.
For the hoses from the tanks to the swirlpot, and swirl pot to pump, go to a marine store and get the 5/8" I D hose - the one with the red stripe (can't remember the brand name, but it is very common). This is ethanol proof and easy to work with. That size is hard to find in auto stores - and as Mark says, not the radiator hose with wire reinforcing.
If you find any dirt/rust, add a temporary in-line filter between the swirlpot and the pump (to protect the pump). If after a time you find no crap in the filter you can bypass it.
Hope this helps.
Wilf.
Instead of ramps you may want to go to your local Harbour Freight and buy the aluminium motorcycle/ATV jack; it only has a 1500 lb capacity, but that is enough to lift the rear to about 19". It is a beautifully made piece of equipment and I'm sure you can find a 20% off coupon.
For the hoses from the tanks to the swirlpot, and swirl pot to pump, go to a marine store and get the 5/8" I D hose - the one with the red stripe (can't remember the brand name, but it is very common). This is ethanol proof and easy to work with. That size is hard to find in auto stores - and as Mark says, not the radiator hose with wire reinforcing.
If you find any dirt/rust, add a temporary in-line filter between the swirlpot and the pump (to protect the pump). If after a time you find no crap in the filter you can bypass it.
Hope this helps.
Wilf.
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