hello I need help identifying a part. I have a 96 3.4 V6 and on the vacuum line to the FPR or the line that comes off the Intake silencer in the upper right this line leads to a relay or some magical electric thing with this vacuum line attached to one side and another leaving the other. What is this thing? and what does it do? The vacuum line attachment is broken on mine and I need to replace it. I have been searching for this and don't even see the part on others engine photos. Thanks Garrett

 

If it is anything like on the earlier engines, see the web page below:
- http://www.4crawler.com/4x4/CheapTri...ine_Pix/8.html

The fuel pressure regulator is modulated by the engine vacuum, high vacuum = low engine load = low fuel pressure, low vacuum = high engine load = high fuel pressure = more fuel flow. The vacuum switching valve is supposed to eliminate some sort of hot start problem by boosting fuel pressure during hot starts to prevent gas from vaporizing. I removed my VSV many years ago and have observed no starting problems, hot, cold or otherwise.

 

Thanks I think thats probably what it is. I suppose when I remove it I just connect the vacuum line and leave the plug hanging?

 

That is what I did on my '85. Some day I might hook up an indicator light to that unused plug just to see when/if it comes on. At least in the early EFI engines, this was only a "feature" on the 4x4 vehicles, on the 2WDs, there was just a direct vacuum line from the intake to the FPR.

More info: