vacuum switching valve broke (bypass?) (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Joined
Aug 11, 2005
Threads
159
Messages
1,911
Location
Sunny South
the VSV (2) for AI, on my 83 fj60 is broke. the PO broke both nipples off of the switch so its inoperable. Can I bypass it, technically its supposed to go from my air cleaner to the VSV to the ABV could i just route it from the air cleaner to the ABV? will this cause any problems? idle issues?


it should be noted that the PO butchered my smog equipment... the air rail has been cut off and plugged with a bolt (semi-bummer) ... so the actual operation of the emissions equipment is most likely rendered useless. just wondering if this idea will affect anything else
 
Bypassing the VSV(2) and running the vacuum line from the ABV straight to the air cleaner is the same as VSV(2) being "open". On the other hand, plugging the port on the ABV and the air cleaner would be the same as VSV(2) being "closed". If your AI system is otherwise not complete, I don't think it matters much which you do. As long as you don't create a large vacuum leak and/or leak unfiltered air into the engine, the AI system does not effect how the engine runs. It only helps to reduce emissions by providing oxygen to further burn residual hydrocarbons and allow the catalytic converter to work properly.
abv operation.JPG
 
I've read these wrong before :hillbilly:, but the way I read the emissions FSM page 3-20, it looks like routing it as you suggest would result in the ABV being constantly open. If you have a functional smog pump, it will constantly push air to the exhaust pipe instead of your non-functional air rail. I think the only difference a working VSV(2) would make in your case (non-op air rail) is that it would direct the smog pump output to the air cleaner like it's supposed to when the cat is hot (assuming your VSV(1) is functional and closes at high temps). In your case, pushing air to the exhaust instead even when it's hot might exacerbate high cat temps.
Butt

EDIT: Of course 2mbb beat me to the punch!
 

Users who are viewing this thread

Back
Top Bottom