I have owned this project since May. It came with a burned out CEL. There were 2 codes: p0440 EVAP(3-1-5) and the terrible long term fuel trim code. Well, the PO also must have known as all of the vacuum elbows were new. I cleared the codes and forgot about them. The fuel mileage was not as good as I expected and what vacuum pressure?

After cleaning up the PCV system and the PTC along with the EGR valve, the vacuum got better, but still not as strong as I liked.

Today, I was in a very long and slow line at Goodwill. After about 15 minutes, the idle changed ever so slightly and the CEL came on! I drove home and learned that it was the EVAP code. While reading about the 3-1-5 error online, it made sense to me that the purge valve finally died. When that happens, the purge valve stays open, the vacuum decreases slightly in the manifold, the mixture is richer due to the draw from the charcoal manifold, and that messes up the long term fuel mixture.

I will test the purge valve this weekend to see if it is open with a cold engine and order a new purge valve. Heck, it is only 20 years old!

Then I will probably sell the project, I ran out of garage space.
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Keeping it running is better than buying new

Ahoy Klaus,

Are you talking about the EVAP valve? I'm not sure what you mean.

A by product of looking at my 850 Volvo files I revisited this document:

SytemComponentTest.pdf

Every 850 Volvo tech should have look at this 10 page PDF file with
a wealth of troubleshooting info concentrated in one place. How to check
lots of key stuff. Maybe you have it?

If anyone doesn't have it, they can try a search for that file or e-mail me.

=================
KLAUS FOR PRESIDENT! *
=================

* This is a political ad directed at the millions of Brickboard fans out there,
some of whom might actually vote. If you're outside the USA and/or not a US citizen, No Problem! Check the website for details of where to send your $$$ and how to vote for KLAUS!

Respectfully, Bill

Campaign manager/Treasurer
offices in Switzerland and somewhere in Argentina
Send $$$ now!

where can i find this SystemComponentTest.pdf ??
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-woodsy; 275k 1995 850 wagon;

Nice web site:

http://www.volvotips.com/index.php/850-2/volvo-850-s70-v70-c70-service-repair-manual/

Just scroll down to system component test, one for NA and the other for turbo.

BTW, The small HVAC line behind the fuel filter was cracked and I replaced it with a piece of 1/4" fuel line I had laying on my workbench. Just 4 inches long, it should never crack again!
--
Keeping it running is better than buying new

marvelous. thank you.
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-woodsy; 275k 1995 850 wagon;

You got my Vote! Vote Klaus!

Hugh

Slightly different than the NA cars, same principle. I removed the valve hanging on the side of the radiator and was able to blow through it, not good. It is glued together, so I tapped it lightly and a 5mm blob of dirt fell out. After that, I could not blow through either side.

I gave it a new silicone vacuum line to connect to the intake manifold, test drove it for 20 miles and all appears to be well. Perhaps it is 'fixed', only time will tell.

I do need to check the HVAC lines by the fuel filter to see if any of them are cracked, but the passenger side of the car is up against the garage wall and jacking it up there is a pain in the back. No gas fumes from that area...

--
Keeping it running is better than buying new