Installing a used VOES, my EFI to Carb conversion.


Have tested the VOES using vac pump and Ohm meter.


It switches as it supposed to.


But, vac is not held.
If I pump it'll switch, soon as I stop pumping vac falls to zero and VOES switches back off.


Is that the way it's supposed to work?

 

It sounds right to me.

Remember the faster you go the more vac you create and the slower you go the less vac you create.

You need the switch to change at the right times.

 

I think it has a leak. It is a switch set at a specific vacuum pressure. When you pump it, it it switches, but when you stop pumping, assuming that your pump has no leaks and can hold pressure, then it should maintain that pressure. If you plug a hose and pull a vacuum on it, it holds when you stop pumping, right? If that's how your pump is, I would get another switch.

 

Vacuum is higher at idle, it is created in the intake manifold or carb by the butterfly or slide being closed..as the butterfly or slide opens (higher RPMs) equals less vacuum due to less restriction. The VOES is pulled on at idle retarding timing and at about 1600 (I think) rpms it is released to full timing advance, works the same as a vacuum advance on a cars distributor. I'm guessing it needs to bleed off to allow the switch to release. Is it not working or causing a problem?

 

That VOES is bad. Should be sealed and not leak off. I went through this. It should hold vacuum.

 

I agree

 

New installation.
Testing it to see if it is functioning properly.


I'm thinking it isn't.

 

I know the electrical connection is in a bad spot, but you can plug and unplug this connection and the idle will change, lower with it unplugged... if no change you are probably looking at a bad VOES. Thinking about this it probably stands to reason that it needs to hold vacuum at all times or it would cause a leak, with all the bad running issues related. I think I would try a new one.

 

The diaphragm in the switch is bad. You need a new one......

 

Ok thanks, I'm going with the bad switch opinion.
I figured it probably was, but thought I'd check as it ain't a cheap part.


O well...


Thanks.