Hey guys,
1996 850T with 112K. I bought it last summer with 94K and have since done the stage 0 stuff. I runs great, gets 27ish mpg and has the obligatory broken spring seat on the passenger side. I had noticed oil around the cap, and when I changed plugs (to volvo turbo) there was oil there too. The dipstick blows out gas so I knew that PCV system was ready for a change, but it ran great and was ready for it to throw a code.

Last week after a fill-up we are idling out of the gas station and it died. Started up in a few seconds, but didn't start up the first time after the stall. I didn't give a check engine light.

Everything ran fine and later that week it set the CEL, and it read P0172- long term rich fuel. Next time I filled up it stalled at the pump. Now the CEL has gone off and it continues to run fine.

The PCV parts are on the way, but my question is:

With the stalling after the fill-up is there something else going on that relates to having the cap of the fuel tank?

Thoughts are appreciated.

Thanks!

 

Maybe evap valve is bad and staying open causing fumes to over come the intake.

 

Is that evap valve part of the pcv system that I'll be replacing?

 

No its a seperate system.

 

I am not familiar with the evap system. Is there a simple way to trouble shoot it? The PCV parts have still not arrived, and it only stalls after a fill-up. But curiously, some times after you fill-up nothing will happen when you turn the key- sometimes the dash lights up, and sometimes it begins to turn the motor over then coughs and stalls. Every other time you start it- no problem, only after the cap has been off the tank. Any more thoughts out there- Thanks Tech!

 

The evap system starts under the hood at the intake. There is a Valve located on the cooling fan.
follow the hose some go to the back of the car and others go to inside the drivers front fender.
Follow the hoses and check for cracks/breaks in the hoses.

 

See if you covered everything on the list; my 2ndreply covers tune-up items.

https://volvoforums.com/m_48928/tm.htm


JPN

 

Thanks guys, I'll check it in the daylight.

 

OK gang, here is the latest update. Car is still stalling only after fill-ups, and last week after sitting for a two days it wouldn't start. Just turned over and over. The next day it did start after a very longer attempt (20-30sec?). I drove it to a trusted Volvo mechanic two hours away (we were out of town when it wouldn't start).

When he pulled to codes it had a new one "Evap System", plus the long term rich. He is puzzled at the symptoms of only stalling after fill-up. He said that the evap canister was not saturated with fuel, and he thinks that it would take liquid fuel getting into the intake to cause the apparent flooding after fill-up.

I appreciate that he did not just start replacing random parts, and he did not charge me for his inconclusive diagnosis. He suggested that I place some clear filters in the evap tubing to see if liquid fuel is passing through the system. But then the question is why would liquid fuel be coming fro the tank. He thinks that a Evap Valve stuck open/ or closed wold not cause this problem. Without the canister wet with fuel he doesn't know what to make of it. Today it started up, drove fine, no CEL for now.

I am going to get out the mirrors and keep inspecting these lines to try to find a problem- up till now I haven't removed items to inspect the lines, but I need to. I think that TECH is on the right track with the EVAP system- is there any way to trouble shoot the EVAP Valve, or just replace it and see if that fixes it?

I plan on only filling up the tank 1/2 way for awhile to see if that helps.

Every time I do something to the car I check hoses and lines (Spark plugs, oil change, cleaning). I've read plenty of post about vacuum leaks, but after searching a few Volvo sites (volvospeed, Matt's volvo site) I haven't found this particular problem.

Thanks

 

I had some similar problems when I first got my '94 when I overfilled the gas tank. I was also having some plug wire issues so it was hard to sort it out. When I fill up now I let the pump go until it clicks and no further. The problem has not re-surfaced since.

...Lee

 

I never try and put another drop in mine once the pump shuts off automatically. I used to keep clicking every drop I could get in, but stopped doing that and can't remember why. This may be the reason, but memory not too good.

 

OK gang, first time I've added gas since last post. Yesterday added 3 gallons- no problem. This morning put in 10 gallons- no problem.

Last night I check all lines, removed the evap canister. I couldn't find any hole, or evidence of any leaks, althought the hoses from the canister to the intake are old looking, and 1/2 dry rotted, the appeared to be functional. I also blew into the lines-

The one to the intake manifold has little resistance, but the line from the tank had lots of resistance- I was unable to blow air through it, but I could suck air towards the canister.

I'll price an evap valve- and it no CEL light comes on, I'll do nothing for now. If the light comes on- I'll post an update. Any other thoughts?

Thanks

 

Last minute reference.


JPN

[IMG]local://upfiles/6892/1A4D522851434F8BB5107A8BBDB8C002.jpg[/IMG]

 

JPN- thanks for the diagram- where do you get these? Google, or do you have the Vardis? I wonder where the 'roll-over valve' is. I did not see it during my inspection last night. It is another component to could be involved in this issue.

THANKS

 

There are a few different locations where you can download PDF version of the factory manual. I got mine at: http://www.volvoclub.org.uk/volvo_wo...techdocs.shtml

Matthew's volvo site also seems to have it in one zip-format package. I print out the pages and scan them to convert them into jpeg files so that I can post them here. Not a necessary step but makes things easier for others + helps me learn the 850 better.


JPN

 

Update:

The car did fine for me- I put gas into it three times, 3 gallons, 10 gallons, and 5 gallon. I stopped it each time at the first click. Drove it a week- no CEL. Traded cars with my wife this weekend.

Today she goes to put gas in it. I had told her not to put in over 10 gallons.

She said it clicked after a 1/2 gallon. She kept putting in gas- she said it clicked 20 times to put in 10 gallons. The car tried to stall when she went to leave the gas station, but then ran fine. The CEL came on as she was driving home from the gas station.

We are currently working in different cities, so I can't lay hands upon the car until Thursday, and I don't think she is keen on taking it somewhere to get the CEL light read.

So, something is wrong with the filler tube/ evap tube assembly.

Other point- there has been lots of pollen recently and it looks as though something has spilled from the gas tank- there are smears around the gas door- maybe a bad cap? Pressure is too high and not being relived by evap tube? Tube is blocked?

My wife said she thought it was wet around the filler tube after she had finished adding 10 gallons.

Any thoughts before I can get my hands on it?

Thanks

 

When it keeps clicking off when pumping gas it's because she has the nozzle in too far. Back the nozzle out a little and it should fill up fine and then just quit the first time it clicks off. Assuming the gas gauge is reading close to full of course. I alway run my tank down below 1/4 before buying gas so I know I should take at least 14 gallons.

 

Tech suggested that the evap valve may be faulty. In read on the site that JPN posted that the evap valve should be closed at idle. When my car is idling there is a good bit of air being sucked in the evap canister. If I block the opening the car stalled. Could someone check their normal car and see if that canister is drawing enough air to make it audible over the engine noise. I'll get to see the car first hand tommorrow.

Thanks.

 

So it took a lot longer than it should have to lay hands on a Fuel Evap valve, but eventually through the help of JPN I got mine from FCP Groton. Installed this morning- went straight to the gas station, filled up and NO STALLING! yeah!

Time will tell if it's fixed for good. I need to get the codes cleared to see if they return- I will continue to update.

Thanks Tech and JPN.

 

Glad the problem seems to have been fixed. See if the car would behave, and if it does for 1-2 weeks then I would say the problem has been solved. Make sure to follow scheduled maintenance.

It was not only Tech & me who helped you but many others have helped you. That's the part I really like about this forum.Regular membersare honest & straightforward, and do not deride at those who're starting to learn. I think this forum is more professional than some shops.

Come back if the problem returns. If not, enjoy the ride.


JPN