MAP sensor vacuum question

[BigBlockOlds]

Does a MAP sensor need to have its own vacuum signal directly from the intake manifold to work properly? Or, can I Tee off another vacuum line as long as its referenced from full manifold vacuum?

Thanks,

[Hammered]

Depends on what you're teeing off of. I would not tee off the same line that goes to a booster or PCV. Either could cause pressure spikes that might affect drivability. However, there shoud be no problem sharing with a similar deadhead device like a fuel regulator.

[BigBlockOlds]

Thanks.

I had thought about the PCV line but noticed that I've never seen anything 'T'd off that line in any application and figured it was for a reason like that.
And since I plan to have the HVAC controls vacuum line going to a vacuum canister, I figured that wouldn't be a good idea either.

This normally wouldn't be a problem but in this case, my intake manifold has zero vacuum ports. I had to add one for my PCV valve but forgot about all of the other things I would need while it was off the engine. So the only one I have left now is a small vacuum port off the base of my throttle body to use.

Thanks,

[PRRC]

Here's another thing to consider. Keep the line as short as possible. or as close to the vacuum source as possible

[Hammered]

You could get a 3/4" to 1" spacer if you have enough room and tap it for a fitting.

[BigBlockOlds]

That's what I've been looking into this evening. It looks like I'll have to run some sort of a cowl hood to clear the intake/throttle body setup I have now so I might as well go a little taller.

Thanks,