Is there a way to test a 98 EVAP system?

[scot850]

I am adding a link to another thread as that thread was losing the focus:

https://www.matthewsvolvosite.com/forum ... 5&start=10

Below is a response to our friend befarrer in Edmonton who had a similar issue. In his case he found a purge valve had failed.

Thanks. That test is simple enough (removing the valve and blowing through it to see if it has failed open) but required the car to be in bits to do the test. At that point I have a car in bits and a long order time (no 98's at junkyards around here currently). Valves are around $115 + Tax each so expensive to buy on spec.

Need to find way to test this without disassembly or taking to dealer as an hours labor is more than the part!

I also need to confirm if there are 2 valves. On the link at the start of this thread there is a diagram of the system and it shows 2 valves. It is not clear if there are 2 options or 2 valves. If 2 valves which to buy? I think it was #11 (Vapor canister purge solenoid valve) and #18 (Vapor canister purge shut off valve)

The issue I have is that it is not clear if there is one or 2 valves in the system, and Vida is of no help in terms of clarifying or giving any testing regime.

I will look at my Autel 802 and see if it is smart enough to cycle the system and test the valve without dis-assembly, but if a pipe has failed this may not work anyway.

Any suggestions?

I will try my laptop with Vol-FCR again as I think I may have figured out the com1 issue (had the wireless mouse plugged into it).
Still can't get my phone and the 850 software to work as I cannot figure out the access pin and none came with it. I did try 0000, 1234, and 4321 but none work.

Thanks,

Neil.

[abscate]

The canister shut off valve is normally open and only closes to test fuel system integrity during the evap cycle.

The canister purge valve is normally closed and is opened with a duty cycle to clean out the canister, and also run the evap cycle test.

You can put 12V on either one to see if it toggles the function correctly

[scot850]

Appreciate the help. Problem is you have to pull the fender liner to get into one of them, so you are already in there. I don't think there is any other way to do this than pull all the stuff out, test it and replace the necessary valves and if the one under the fender guard needs replaced, then just put a few rivet in to hold it in place until part arrives.

Neil.

[befarrer]

Another problem with EVAP codes is that they take a couple of engine warm up cycles before they trigger a code. I had an equinox with a bad canister valve, the one that controls vapors from the tank to the charcoal canister. It was stuck closed, and it made refueling a pain, the pump nozzle kept clicking off at anything over 1/4 trigger. Fuel tank also hissed to relieve pressure when I opened the fill cap.

[scot850]

Been there with the filling issue. Even the reverse where a car stopped running as a vent jammed closed and caused such a vacuum the pump could not draw gas from the tank!

I understand how the system works, but hoped there may have been a way to trigger the system to check the valves.

Looks like I will have to do this the hard way.

Neil.

[scot850]

Befarrer, which valve was it that failed? The one between the inner and outer fender behind the LH front wheel, or the other one. Can't recall where it is sited. It may be on the LH rear of the radiator area.

Thanks,

Neil.

[befarrer]

The one that failed on me was between the throttle body and the rad. On the hose that goes into the intakem

[scot850]

Many thanks for the clarification. Good thing is that at least if the other one is ok and having fitted new pipes under the fender area, if the valve turns out to to be bad I can easily access it to replace later.

Neil.

[Eddystone]

I think I posted this previously, but after chasing down an evap error on my 1998 V7 non-turbo, I came to the conclusion that if you don't smoke test the system, you are ALWAYS wasting time and money. A visual check of the hoses, and then smoke test.

Aftermarket purge valves (near radiator) are only $11 on Amazon if you want one to troubleshoot with.

Pulling the fender inner liner is just something you have to do on a 98 like yours and mine because that's where the hoses and cannister and rollover valve are. As with everything else, the first time you do it it seems hard. Second time you do it takes you 15 minutes. You simply drill out the existing plastic rivets. In my case, I went to Harbor freight or Amazon and got an assortment of plastic rivets which are easy peasy to use and can be used elsewhere on the car for mud flaps and so forth.

Make a smoke tester from a pickle jar and soldering iron a la Youtube.

[scot850]

Thanks Eddystone. Good advice. I will check the price of a valve on Amazon, but expect the 200% + Canada price add-on.

Neil.