Evaporative Emissions 1998 V70 non-turbo

Post by **Eddystone** » 25 Oct 2019, 09:57

Still getting OBDII code for Evap Emissions. This is my car's arrangement:

https://parts.volvocarslisle.com/a/Volv ... 74761.html

https://parts.volvocarslisle.com/a/Volv ... 71750.html

https://parts.volvocarslisle.com/a/Volv ... 78647.html

1. My car has carbon canister in front of left side front wheel. Took inner fender down. Long hose looked iffy. Replaced it. Two small tubes going out of canister were pliable and seem fine. Big tube apparently goes to rollover safety valve???
2. Go to front of car at radiator. Tube going to solenoid from canister seem fine This is non-turbo, so there is simply one hose going to the intake manifold from the solenoid. It is fine, also.
3. The other tube from the canister goes to the back of the car and fuel tank. Recently replace fuel filter. Short hose up behind fuel filter with different diameters at each end was replaced with an OEM replacement part. Old hose here was pretty crumbly.
4. As far as I can see, if there is a hose issue, it would have to be up on top of the gas tank where the fuel pump and sender are. Access to the end of that hose is limited.
5. QUESTION: Could the solenoid just be bad? The connector is very clean and has been unplugged several times. Is there a way to observe the solenoid in action? When would it operate?
6. QUESTION: How about this little filter between the canister and the solenoid? Could this be blocked? I have been looking for an open hose, not a blockage.

I have a rudimentary homemade smoke generator, but it is hard to use when you are working alone, and hard to know where to try to break into the circuit. I would rather not have to remove the fender liner again and have to drill out all the plastic rivets I reassembled it with.

Ideas?

Remember, I do not have a canister in the back of the car and no J-hose back there.

Post by **Eddystone** » 25 Oct 2019, 13:48

No bites? No nibbles?

Post by **abscate** » 25 Oct 2019, 14:06

Purge is called for by the ECU and the code isnt really known here. I monitored mine once and it seemed to draw on the canister about every 20 minutes or so at highway speed, for about one minute

There is no substitute for getting down and dirty and tracking down the leaks with smoke, IMHE

Post by **erikv11** » 25 Oct 2019, 16:49

abscate wrote: ↑25 Oct 2019, 14:06 Purge is called for by the ECU and the code isnt really known here. I monitored mine once and it seemed to draw on the canister about every 20 minutes or so at highway speed, for about one minute

There is no substitute for getting down and dirty and tracking down the leaks with smoke, IMHE

E can't be H though. Dept. of EH & BS.

Post by **Eddystone** » 25 Oct 2019, 20:30

abscate wrote: ↑25 Oct 2019, 14:06 Purge is called for by the ECU and the code isnt really known here. I monitored mine once and it seemed to draw on the canister about every 20 minutes or so at highway speed, for about one minute

There is no substitute for getting down and dirty and tracking down the leaks with smoke, IMHE

Bring me up to speed on the shut-off valve that in my car is under the driver's front fender. Is this intended to keep the gasoline from pumping or leaking in the event of a rollover or accident? I have heard that these can get stuck. Open? Closed? I don't quite understand how that is connected or how it functions.

I guess the only way to really check for leaks is to inject smoke into the tubes that come OFF of the canister where the rubber connectors are reduced to the plastic pipes. I might just be able to get at those ends from under the car in the front.

Post by **abscate** » 25 Oct 2019, 20:59

The shut off valve isn’t there for Evap function, it’s for testing. The system does a fairly complex cycle of pumping out the tank, watching the leak rate, etc....and determines which parts of the system have problems.

User Lexia posted a great treatise on this , you can search or its bookmarked in my Maintenance thread

Post by **Eddystone** » 25 Oct 2019, 21:51

abscate wrote: ↑25 Oct 2019, 20:59 The shut off valve isn’t there for Evap function, it’s for testing. The system does a fairly complex cycle of pumping out the tank, watching the leak rate, etc....and determines which parts of the system have problems.

User Lexia posted a great treatise on this , you can search or its bookmarked in my Maintenance thread

Yes, I have read it all. Thanks.

Post by **abscate** » 26 Oct 2019, 04:10

erikv11 wrote: ↑25 Oct 2019, 16:49
abscate wrote: ↑25 Oct 2019, 14:06 Purge is called for by the ECU and the code isnt really known here. I monitored mine once and it seemed to draw on the canister about every 20 minutes or so at highway speed, for about one minute

There is no substitute for getting down and dirty and tracking down the leaks with smoke, IMHE
E can't be H though. Dept. of EH & BS.

But you can be H-Ed by E, IMHE

Post by **Eddystone** » 31 Oct 2019, 16:14

Just to wrap this up in case anyone is reading with a similar problem, there were two problems that gave me the Evap Emissions code:

1. In the '98 the canister is in the left front fender and there is a large diameter hose going from the canister to the purge valve (or pump) also located inside the fender by more to the rear. This hose was in bad shape and leaking. I replaced it with some cheap vinyl tubing I had on hand, and that was a mistake. See below.
2. There is a 2-inch long hose hidden behind the fuel filter in the back of the car was all old an gnarly and cracked. This is the one with two different diameters at each end. I replaced this and thought I had solved the problem.
3. When the code returned, I removed the inner fender liner to gain access to the canister again and found that the vinyl hose I had installed had KINKED by being bent over blocking the air flow. I replaced this with a proper fuel-grade hose which was sized correctly, and I THINK that the code is gone for good. It does take a while to show up so that you can be sure it is fixed.