98 V70 gas tank - possible vapor build up issues

[98v70dad]

If checking the roll-over valve and in-line air filter as suggested above don't help resolve the fill-up problem, I'd recommend checking the charcoal canister and the canister vent valve. Both of those must allow air to pass during fill up.

The roll over valve is pretty new (2 years) although that doesn't mean it hasn't failed. The canister was OK last time I checked it, but that was also 2 years ago. I'm not familiar with the canister vent valve ... is that the same thing as the purge valve?

[98v70dad]

For the elbow to the intake, it is much easier to just replace the whole line with one piece of rubber or silicone vacuum line. That way you can just pick up what you need from any auto parts store.

I thought about just using vacuum line and I'm sure it would work. What has kept me from doing that is the nagging question of "why is this done differently"? I've never seen a plastic line like that in any other car I've owned and it would have been easier and cheaper to use the vacuum line at the factory. So, there must be a reason its done the way it is, I just dont know what it is. That said two feet of vacuum hose is about 2 dollars. I can always put the old part back on if it doesnt work out.

[erikv11]

For what it's worth, dozens of people have replaced the entire set of vacuum lines with silicone with no apparent ill effects. None apparent anyway.

All my P80 cars suffer from the quick shut off on fill-up at certain gas stations, I thought it was related to fill hose/valves on the gas pump rather than to anything changing on the car. I have found that if you rotate the handle about 15 more degrees clockwise (you have to hold it there, can't walk away and check the oil) then you can run the pumps at full blast until the tank is full.

[98v70dad]

For what it's worth, dozens of people have replaced the entire set of vacuum lines with silicone with no apparent ill effects. None apparent anyway.

All my P80 cars suffer from the quick shut off on fill-up at certain gas stations, I thought it was related to fill hose/valves on the gas pump rather than to anything changing on the car. I have found that if you rotate the handle about 15 more degrees clockwise (you have to hold it there, can't walk away and check the oil) then you can run the pumps at full blast until the tank is full.

Thanks. The shut off at fill up is minor annoyance. I just thout it might be related to my P0172, P0440 codes. I replaced the line from the throttle body to the air filter box and I'm still getting the codes. Usually the 0172 and occasionaly 017 and 440. I guess I'll just have to keep after it. Eventually I'll figure it out.

[erikv11]

You may have checked already, I didn't review the tread, but since you said p0172: is the elbow and line good on the passenger side of the intake manifold?

[98v70dad]

You may have checked already, I didn't review the tread, but since you said p0172: is the elbow and line good on the passenger side of the intake manifold?

Yes, I think so. I inspected it and amazingly it looked nearly new so I didn't replace it. I bought a new one and have it standing by if I need it. When I did the PCV system upgrade I got rid of the plastic tube that ran under the manifold and replaced it with a piece of brake line with a 90 degree bend on the passenger side. The line runs on top of the manifold along the front of the fuel rail. The brake line fits snugly in the 90 rubber elbow but I cinched it on tight with a screw clamp. The rubber 90 elbow is just pushed onto the manifold with no clamp.

So, my brake line idea has me out there on my own a bit, but I really think its much better than the original design. The brake line was pretty cheap also.

[erikv11]

Yeah, that sounds like a pretty good fix. I figured you were aware of that one but wanted to ask.

[98v70dad]

So I replaced the purge valve with a volvo part and the filter next to it this weekend and so far no codes. The old filter was absolutely filthy. I dont know if it was plugged. I didnt think about checking it until it was buried under two days of garbage. I'm not going to dig it out.

Also, I filled the gas tank this evening and buried the gas pump nozzle into the filler neck. The pump didn't shut off or skip a beat. I put in 12 gallons at max velocity and the pump didn't shut off. I dont know if this was a coincidence or just good luck, but this hasnt happened for at least 2 years.

[erikv11]

This is interesting. Which filter are you talking about, is it something on the filler neck like Neil posted about?

[98v70dad]

This is interesting. Which filter are you talking about, is it something on the filler neck like Neil posted about?

There is a little filter between the purge valve and the charcoal canister. It looks like a lawn mower fuel line filter and is located about 4 inches away from the purge valve in the engine area just aft of the radiator on the drivers side. I've read that most people remove them because they "only cause problems". For whatever reason I left mine installed. It cost 6 bucks and since I already shelled out 102 for he purge valve, I splurged. I'm just wondering if the purging wasn't happening because the line was plugged. Working now, at least for 100 miles ...we'll see.