Can you tell by just a vacuum test if you have bad rings or not?

[jimdigs]

I have blow by and am only getting 39/40mpg after a ton of replacement of parts and what not. I have come to the conclusion that my rings are bad (low compression test) but when I do a vacuum test it stays in the 19 range but does flutter but not more than an inch. Wouldn't the vacuum test show bad compression as well? 93 5 speed. I still can't shake the feeling that there is something else going on that is costing me the gas mileage I should be getting.

[Chobobulous]

What are your compression numbers?

[bravekozak]

Like Chobob said, bad rings are diagnosed with a compression tester.

[jimdigs]

What are your compression numbers?

145 120 145 115 Also, is it normal for the engine to die immediately when pulling a vacuum line, because mine does?

[Chobobulous]

Is that wet or dry?

[jimdigs]

Dry, I didn't do a wet test. I need to but I'm sure its the rings not valves.

[SiliconSoul]

Pretty sure a big vacuum leak will stall most cars.

As far as numbers go, yeah, those are a bit on the low side. On the bright side, your still getting 30/40mpg on a worn engine!

[WmWatt]

My car dies when one vacuum hose is removed. Don't know if that applies to all hoses at all connections.
Check the permanent thread about vacuum diagnosing at the top of this forum.
I recall it is an indicator for worn or dirty valves. Not sure about rings.
Usual test for worn oil seal rings is wet and dry compression.

Cylinder pressure should not vary by more than 5% across cylinders.
You seem to have a problem there.
I once had a low reading on #3. When I removed the valve cover and
turned it upside down I could see carbon deposits above the #3 exhaust valve.
Thinking there might be carbon buidup, possibly crystalization, preventing the valve from
fully closing, I used chemical cleaner which must have dissolved the carbon because
the compression went back up to within 5% of all the other cylinders. Has stayed up.
Good luck.