Aloha,
I have an ongoing issue with the evap bypass solenoid going off constantly. I have noticed it goes off when the car is parked...it stops when I remove the gas cap...& it goes off even when the battery is disconnected. The car hasnt thrown any DTCs, but it continuosly fails the evap IM test.
Im picking its a kinked hose or a blocked valve, but the damn car is only 3 inches off the ground & impossible to check out without lifting it...& to tell you the truth, I have been too busy replacing O2 sensors & ignition switches to get round to it. The wife keeps hassling me about it, so its a matter of pride now to fix it. The FTP sensor voltage is OK, but I havent checked it out with a vacuum gauge yet.
Any suggestions ?.
PS...I scored a FSM for the 1998-2002 Accords last week for $36 from here:
www dot autorepairmanuals dot biz
Ordered the CD Rom & it got down to Hawaii in about a week. They have an amazing library of FSMs going back to the 1920s...well worth checking out. Im trying to figure out how to post pages from it to this forum, but Im not that great at Adobe Acrobat. I can print pages, so maybe I can scan those & upload them.

 

Where is the evap bypass solenoid on your car?

And what is an IM test?

 

With the bypass valve, under the car in front of the gas tank
IM test is the Mode 6 emmisions test

 

Since you have an owner's manual, take a look at the wiring for that valve. I don't think it is controlled by vacuum. You will have to see if the ECU is supplying ground or voltage to operate that valve.

To make a pdf using acrobat, open up the pdf. Then click print. Select adobe pdf as the printer and you can select the pages you want to print. Current page would be one page, etc... The adobe pdf "printer" just saves the pdf file on your computer. You can create pdfs using any program where you can print.

 

I changed that link; active links to selling sites are not allowed (except sponsors). You can refer to websites the way I made it.

Look for something called "pdf995" it's a free pdf writer. Not as powerful as the genuine Adobe Acrobat, but it's free.

Are you sure it's the EVAP bypass solenoid going off? (like seeing it with a scan tool) With the battery disconnected, it's hard to believe any solenoids are actually working. But I think the 3-way valve can open up with fueltank pressure, kinda like a pressure-relief valve. That's how it's supposed to work. Some are quieter than others...

 

Yes, I was surprised to hear it operate with the battery disconnected myself. I was able to place my hand on the component as it was operating, & it stopped the instant I relieved pressure by opening the fuel cap. I'll get her on my friends hoist this weekend & check it out. I was thinking a blocked valve, or a blocked or kinked hose & with the FSM it shouldnt take much too much effort to trace the problem. The tank IS pressurizing, so I just need to figure out why.
Sorry about the link, but with so many people looking for FSMs, I thought it would be appropriate.

 

Another way of posting things like that. For windows, use the "print screen" function, then paste into "paint" or something...then you can edit/crop or whatever in "paint" and save as a jpg. Then upload the jpg.

 

Thanks PM212,
I'll give it a go !.

 

The 2-way valve is #14 in the picture below (I mistakenly called it a 3-way valve). But it's located inside a plastic shroud, #28.


That 2-way valve isn't a solenoid valve, but it opens a vent allowing the fuel tank to vent through the EVAP canister whenever the fuel tank pressure gets high enough.

The fuel tank will pressurize itself simply from gasoline evaporating. That's normal.

 

Thanks JB...excellent diagram. So the valve is just purging into the Evap cannister as it is supposed to do. It just keeps doing it repeatedly for about 2 - 3 hours after the car is parked (& freaks my wife out ! LOL). Would you suggest looking for obstructions/blocked cannister...or is it normal..?