If anyone has fitted a manifold vacuum/pressure gauge to their JK, was wondering where on the intake manifold you installed the fitting for the vacuum hose to the gauge and what method & connections you used? I've installed them before but only on carburetted, aluminum-manifolded I6's so am unsure about optimal placement of the hose connector an in injected V6. I'm also assuming that the design is the same (as it was 25-odd years ago), where a vacuum hose runs from the manifold to the gauge; or do the modern ones have sender units on the manifolds and wiring running to the gauge?

Thanks in advance!

 

I thought about the same thing. Vacuum gauge is pretty nice to have.

Would be kind of depressing sometimes though to literally see how much fuel the JK is actually using. I have not seen this particular gauge come up on the forum but hopefully someone chimes in.

 

There are vacuum fittings already on the upper plenum. Install a T fitting on one of those.

I think they are on the back of the plenum, but don't know for sure.

 

Thanks for that; I'll go & have a look. I'd rather not be drilling into the plastic cover or alloy plenum if I can avoid it. Easier to bring back to stock for warranty work.

Cheers!

 

Is manifold vacuum on the CAN bus? If so, there may be answers to get it via devices that connect to it, and provide dozens of other readings as well. If you're running an Android phone, there's even an app that can wirelessly connect up to a cheap adapter to allow CAN bus readings on your phone--they appear as customizable gauges on the phone. Here's a video (not mine) ...

Torque on Evo 4G YouTube Video

 

I don't believe so unfortunately. Was reading on the Aeroforce gauge site about all the reads it displays for different manufacturers systems and manifold vacuum wasn't supported by Chrysler's CANBUS (apparantly it's pretty primitive compared to the other systems from Ford, GM etc).

The two reads I wanted were oil pressure and manifold vacuum; both not available via CANBUS on the JK (to get them to display on an Aeroforce gauge I'd have to use the additional analogue connections on the back & run seperate sensors).

 

Vacuum IS available on the CANBus. It's called Manifold Absolute Pressure (MAP). It's in kPa.

33 to 34 kPa is what mine idles at, all warmed up, in neutral, 650 rpm.

Approximately 101 kPa represents standard atmospheric pressure. That's what the MAP approaches at WOT.

 

That torque app is pretty sweet. I may very well have to invest in a wireless obd II device now.