Vacuum line question

[drewe]

Hey all - I am just 'fixing' my lines to the vacuum advance - it seems to have normal size lines on each end and then this thinner stuff in the middle - some of the other lines have it too - like a joiner, but it obvioulsy has much less volume (with flow being affected by the diameter to the power of 4!) - is that how your lines are? Or are they one line from start to end?

I am about to do some replacing, want to check if what I have is right, or as i suspect, bodge!

Thanks again
Drewe

[senergy]

the joiner could be a one way valve.
or even a tempreture controlled valve.

[murcod]

The two vacuum lines to the distributor are small diameter PVC type hard tubing. At each end there is larger diameter rubber hosing that it slides into. IIRC the sub-vacuum advance goes straight to the advance unit on the distributor, but the vacuum advance also goes to the fuel pressure reg? If you're not sure which line is which=> the vac advance will have lots of vacuum at idle; the sub vac advance doesn't have vacuum until the throttle is opened slightly.

Out of interest I've been running mine with the vacuum advance line disconnected to see what the effects are on detonation. The idle is a lot smoother (and of course lower RPMs - but I haven't had to adjust it up at all.)

[drewe]

Cool - then the hard ubing is real, not just a bodge the last owner did!
Yay!

[rowdy24]

I am not sure what you mean murcod about what pipe goes where.

Currently the upper pipe coming from the vacuum advance goes straight into the throttle body, and the lower pipe braches off some where down the track.

Is this correct, or have I got them the wrong way around?

[rowdy24]

My mistake, I had them wrong, according to the two diagrams below.

[drewe]

I just redid most of them (still working through!), car is running better....

hint - don't just replace one - I only did one not the other first time - got 80 k's less out of the tank and hardly ran! Oh well.

Can anyone tell me what the 'idle up VSV' thing is?

[murcod]

Can anyone tell me what the 'idle up VSV' thing is?

It increases the idle speed (ie. valve opens) when high electrical loads are on. Items such as the headlights and heater fan activate it IIRC.

If you've got aircon there will be another valve mounted on the side of the inlet manifold that does a similar thing when the aircon is on. The aircon one is adjustable to control the idle speed - the one above isn't.