vacuum test
Can someone tell me what it means when setting idle and you punch the gas and the needle on the vacuum gauge doesnt go all the way to 0.What does this mean?I have reved it as high as 3000rpms and it d...
Forum Discussion
joe0508 wrote:There is a port on the LH side of the TBI right above the manifold. That's where I installed mine. When at WOT it will get pretty close to 0 about 1. At idle it should read about 21. When descending a hill it gear it will go higher. I made a pointer out of a piece of black tape on mine at 10 so I can see it at a glance because at 10 or above I get the best fuel economy in 4th gear. Make sure your dog house cover is not compressing the rubber hose that will reduce your readings. I made a steel bushing that the rubber hose goes through to prevent that. I am old so I think the vacuum gauge is a good tool for an older eng, carb or TBI. You can tell at a glance as to how your eng is running (sticking or burnt valves, bad rings etc). Also allows you to stay in 4th gear when climbing a hill by adjusting the throttle at a given reading. Hopes this helps you Joe.
What are my options as far a unported vacuum sources?
