Purpose of VTV and check valve?

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B

BackFromTheDead

10 Year 15 Year
Joined
Apr 3, 2007
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25
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Location
Long Branch, NJ
Hello,

While replacing all my vacuum lines, I accidentally broke the blue VTV valve, the check Valve, and a little 3-way vacuum line spliiter or connector, which I can't find online:

Anyone know if there really NEED to be replaced, if I'm not driving at high altitude, really cold weather, etc.? And also, if they do need to be replaced, a good place to get them inexpensively?
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Where did you find that chart Beaufort? Just curious as I don't recall seeing it in the FSMs.

BFTD - you should be able to get all of those from Cruiserparts.net or somebody here that's parting a 60. Even if it isn't on the cruiserparts website, you can send them an e-mail inquiry and they will give you a price.

I don't know what the actual impact would be of removing them. I think I would be hesitant to remove a check valve, however.
 
I don't know about the check valve, but I bet you could find a similar 3 way splitter at a parts store. Most of them have vacuum hose stuff.

As for the VTV, mine was broken and hanging loose when I got the truck. I took it off, plugged both fittings it attached to, and it's been like that for 1.5 years. Runs great.
 
I did the same thing as Forestdan but haven't had it in over 3 yrs, but now my truck is having idling problems. I was hoping someone could suggest where to get a new vtv.
 
The VTV is part of the Air Injection system. It controls how fast the air bypass valve opens.

The check valve is part of the high altitude compensation system. at high altitude the distributor is advanced an additional 6 degrees. The check valve holds the advance even when the manifold vacuum drops.
 
In one direction the VTV's are supposed to restric, but not prevent flow. In the other direction, it should allow unrestricted air flow. If the flow one way is stopped, then the emissions system the VTV is associated with won't work properly.
 
commando71 said:
Does anyone know what happens if these become restricted flowing in one direction? The FSM says to replace them if air doesnt flow both ways.
Click to expand...


Out a hose on the outflow side of the restricted end. Put the other end of the hose in water and blow to look for bubbles. Usually the flow is restricted enough that you'll only get a trickle of bubbles.
 
Old threads never die... they just continue to help others along the way. Noticed that I broke my VSV valve during my recent work. Going to try and superglue it, but thinking of leaving it out as I have no emissions to pass.

Question - if I leave it out, should I plug the lines, or just run one vacuum where the VSV valve used to be?
 
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