help diagnosing new vac. readings

jaymac

New Member
Feb 18, 2004
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Northern Mass
So this morning I checked vac readings w/ the mitivac again for shiiits and giggles, and tried a few new ports. This time, it fluctuated extremely rapidly between 18-19, the between 18.5 and 19. The needle was a blur between the numbers, and never steadied out, even after a few minutes. A few nights ago, it was steady @ 19 ish. Now it's going haywire.
Any ideas as to why or what to do first?
Thanks as always,
J
 
A lot of it depends upon where the gauge is hooked up, in terms of seeing slight pulsing of the needle. Some spots see more 'buffered' readings.

In general, a tiny twitch like that can be considered normal or can be attributed to a slight ignition glitch.

What happens if you connect the source hose where you had it initially? If it goes back to normal, I would not sweat it.

Good luck.
 
I tried once @ the front of the intake where the charcoal canister connect, then once on the A/C port on the tree, which is right next to the line I tried yesterday.
I will try the initial port again, then report back...
 
Sounds good. Also, if you slightly pinch the vac line, that can quell the reading (it can be very normal for it to fluctuate a little, like yours does. You just want to make sure the range of fluctuation is very small). The adapter fittings that come with the kit often do this too (dampen readings).

If you feel like it, Google vacuum gauge charts. I once found one that had animated readings (like it showed how the gauge fluctuated in real time) and told you what they meant. I look in my saved stuff for several minutes to post the link and cant find it (dial up sucks for doing internet searches or I would find it again).
 
I tried to goolge vaccharts, but got 7 million pop-ps instead (virus problems).
Anyway, I hooked it up again and it sat between 20 and 19.5 again, buzzing back and forth between the two. I didn't get to try any tricks or variations, because it started downpouring on me :(
Maybe later!
 
That reading sounds great. Sorry you could not find the chart I was talking about. I couldnt either - it was kinda neat. Ill look later.

Yeah, internet searches suck because every given page takes 5 minutes to load. I dont even want to try or see DSL or cable because it will make me unhappy. It would be like if someone never drove anything but a stang - he/she thinks it is fast. If he/she rode in a Viper or something, he/she would think of the stang as a slug afterwards. :D