lightning series3
New Member
Hi probably a stipid question bit I want to fit a vacuum gauge to my 3.9 efi v8 . Would I connect it to the pipe from dizzy to plenum chamber . Or would this affect the dizzy .
My vacume gauge is connected directly to the small pipe at the very back of the plenum cover. The ignition advance vacume take off is before the butterfly and I doubt you'll see enough vacume here for the gauge to work. Most vacume gauges run 0 to -1 bar mine from the plenum sits around -0.6 bar at idle.
This is what I thought, but that little pipe above the throttle butterfly seems to be on the air filter side of things, and when I tried is definitely has less vacuum than the pipe at the rear of the plenum. My vacuum gauge would barely register on that throttle inlet pipe, unless of course I have issues and that pipe is somehow blocked?
