can't fill gas tank past about 15 gallons

[zhenya]

On my 850 I've been having some trouble filling it. Last week I really struggled to get it to take any fuel at all, and gave up at about 14-15 gallons with it clicking off every gallon or less. (Yes, I moved the nozzle to all different positions). Today (same station, different pump) it worked fine until it hit about 13 gallons then I was able to slowly add a couple more with it clicking off every few seconds. This is from near empty, having driven 10-20 miles after the fuel light came on.

I've read everything I can find on this issue and I gather that there is a filter near the filler neck that gets clogged, or something in the lines or check valve near the charcoal canister in the driver's fender. Looking around and under near the filler neck I can follow it from tank to gas cap, but can't locate anything other than lines contained inside some kind of plastic cover.

Where should I be looking and how should I start here?

[m96ag]

On my 850 I've been having some trouble filling it. Last week I really struggled to get it to take any fuel at all, and gave up at about 14-15 gallons with it clicking off every gallon or less. (Yes, I moved the nozzle to all different positions). Today (same station, different pump) it worked fine until it hit about 13 gallons then I was able to slowly add a couple more with it clicking off every few seconds. This is from near empty, having driven 10-20 miles after the fuel light came on.

I've read everything I can find on this issue and I gather that there is a filter near the filler neck that gets clogged, or something in the lines or check valve near the charcoal canister in the driver's fender. Looking around and under near the filler neck I can follow it from tank to gas cap, but can't locate anything other than lines contained inside some kind of plastic cover.

Where should I be looking and how should I start here?

The vent tube is probably plugged up. Fuel vent hose repair without dropping tank

[zhenya]

Hmm. I saw that thread but glossed over it because I don't have a gas smell. I also ran across some posts indicating there was some sort of filter that they easily accessed (I thought near the filler neck) that gets clogged. No CEL's in the past 500 miles or so.

[scot850]

I have a theory that those folks who constantly top off the fuel tank when filling end up flooding the carbon canister. This prevents the air from escaping the fuel tank when filling. The other 2 culprits are the roll over valve jamming or partially jamming (causes the same issue) or the filter in the breather pipe from the rollover valve to the outside world. Normally if the car is fitted with this it is at the top of the fuel filler pipe in a 2 piece plastic housing that can be fragile with age. Not all cars are fitted with tis filer as I understand.

Neil.

[zhenya]

Yeah, as I'm learning how the system works I'm thinking that perhaps the ORVR valve is flaky. I believe that would explain why it was difficult to get any fuel into it last time, and could explain why it was somewhat difficult this time. From what I understand the vent valve (roll-over) should only be active as the tank fills to the top, closing the ORVR valve via a float. The vent alone is probably not sufficient to vent pressure to the canister as you rapidly fill the tank. Or it could just be the filter from the EVAP canister shut-off valve which would also prevent vapor escape. Still not sure where to locate that filter though.

I have not opened that black plastic cover that contains most of the filler pipe. Do I need to pry that open to gain access to the filter from the breather pipe?

[beigg]

When was the last time the fuel filter was replaced?

[rspi]

Here is my take...

The car is old and the sending unit is bad. Telling the cluster that you have 2 gallons left when you actually have 5. So you think you are down to 2 and need to pump 17 but you actually have 5 and can only pump 14.

I drive all the time until my low fuel light comes on. Then my "miles to empty" counts down telling me that I have x miles to empty. So, on the road, I usually pump when it says I am 30 miles from empty which should be less than 2 gallons. So I fill up and can only pump 15-1/2 gallons which means I only have about 16 or 17 gallons.

Perfect example has been the past few days. Tuesday... 40 miles to empty. So I drive about 30 miles that day. Wednesday it starts out 30 miles to empty... So I drive about 20 miles. Thursday it starts out 25 miles to empty, 2nd trip 40 miles to empty, about 60 miles later I finally get gas and it takes about 16.8.

I think the best thing to do is get a gallon or two of gas and put it in the back. Drive the car until it runs out of gas. Add the gas from the jugs and go fill it up. I have done this before, the car will sputter before it runs totally out. When it starts sputtering, pull over, shut the car off, add the gas and go fill it up. DO NOT BURN UP YOUR FUEL PUMP BY TRING TO DRIVE WHEN IT RUNS OUT OF GAS. Pull over and add the gas from your jugs immediately and you'll be fine.

[zhenya]

When was the last time the fuel filter was replaced?

About 50k ago or ~6 years.

Here is my take...

The car is old and the sending unit is bad. Telling the cluster that you have 2 gallons left when you actually have 5. So you think you are down to 2 and need to pump 17 but you actually have 5 and can only pump 14.

I drive all the time until my low fuel light comes on. Then my "miles to empty" counts down telling me that I have x miles to empty. So, on the road, I usually pump when it says I am 30 miles from empty which should be less than 2 gallons. So I fill up and can only pump 15-1/2 gallons which means I only have about 16 or 17 gallons.

Perfect example has been the past few days. Tuesday... 40 miles to empty. So I drive about 30 miles that day. Wednesday it starts out 30 miles to empty... So I drive about 20 miles. Thursday it starts out 25 miles to empty, 2nd trip 40 miles to empty, about 60 miles later I finally get gas and it takes about 16.8.

I think the best thing to do is get a gallon or two of gas and put it in the back. Drive the car until it runs out of gas. Add the gas from the jugs and go fill it up. I have done this before, the car will sputter before it runs totally out. When it starts sputtering, pull over, shut the car off, add the gas and go fill it up. DO NOT BURN UP YOUR FUEL PUMP BY TRING TO DRIVE WHEN IT RUNS OUT OF GAS. Pull over and add the gas from your jugs immediately and you'll be fine.

The only thing I see wrong with this theory is that the previous time I had a hard time getting any fuel into the tank at all. I'm fairly sure I have an obstruction somewhere in the evap vent system.

I'd like to check the filter but I'm still not clear on where to locate it. Multiple people have said it is near the filler neck, but my charcoal canister is way up in front of the driver's side wheel. I can't imagine they'd run a vent hose all the way back to the furthest point of the car from there. Perhaps the filter is at the filler neck on models where the canister is moved to the rear of the car?

Can anyone help me locate this filter? Give me a picture?

[scot850]

Don't think you have the filter. As far as I can see, none of the 850's do as none show on Vida with the carbon canister at the rear, not even the 850 AWD version. If you have a plastic shroud around the filler neck, it looks like it houses what looks like 2 small expansion tanks with pipes and possibly 3 small pipes coming from there. 1 pipe goes to the top of the fuel tank which will be a vent pipe to allow air to escape. I can't tell from Vida where the 2 other pipes go. 1 seems to not go anywhere on Vida, and the other I believe links to the evap pipe to the front of the car. This link should help with the tank end:

http://www.volvopartswebstore.com/showA ... evel=24662

And this one the carbon filter assembly at the front:

http://www.volvopartswebstore.com/showA ... evel=24662

Neil.

[beigg]

You may be experiencing a sticking ASV. I am not sure if there is an easy way to defeat that siphoning prevention mechanism to ensure it's properly operating, however, the possible archaic way to check could work for your situation in checking that ASV.

What you'd need is a durable yet slender petroleum safe monad section of material that will fit through the smallest point of the filler neck passages. Smallest dia. should not be under .25" unless it's screened, which if screened, changes the potential positive outcomes for checking. The material being used has to also be long enough to reach the lowest midpoint of the vehicle from two feet outward of the fuel filler neck's entry point. It is advised for any adroit tool being used should be one continuous piece with not junctions or splices at any point. To mitigate introducing more repairs; no taping, adhering, threading, or welding together of materials. Keep it one piece for peace of mind.

Prior to actioning the shrewd probing tool, it might be a great idea to putting equally placed points of references along the material. The indelible references will come in handy.

Starting at the entry point of the filler neck, feed in the probing tool from the entry point, taking note of how much is being fed in through the opening.
As it is blindingly be routed, feel for obstruction and carefully persuade the tool through the impedances. If not possible, back off the tool and try another position for another way past the obstruction. Should you find no other free areas for passing more material in, the blockage might be identified. Before pulling the tool out, record the amount of material that was used to reach that suspected trouble area.

Compare the distance traveled to the viewable length of filler neck to tank distance. Does it coincide to reason the assumed fault?