Cyl Vacuum Wave Forms On A Verus Pro

[BEELINERG]

I was wondering if there is any way to set up a cylinder efficiency test with a vacuum pressure transducer on the verus pro?

[Witsend]

Probably could use a trigger off cyl
#1 fuel injector for one channel and attach the pressure vacuum transducer to manifold vacuum on another channel .
I would probably use the Amp Probe over the battery cable and identify low compression by differences in amperage draw of starter

[sbreland73]

I would recommend using the spark of #1 cyl to set the base time correct. Using an injector will throw you off a few degrees, as the piston is on the intake stroke when the injector fires.

[Witsend]

I would recommend using the spark of #1 cyl to set the base time correct. Using an injector will throw you off a few degrees, as the piston is on the intake stroke when the injector fires.

Trouble is on waste spark systems the spark is occurring twice as often , so you have to divide the rpm by 2 and then determine if the suspect cylinder is cylinder one or four , or cylinder 3 or cylinder 2, unless you can see the KV difference and determine which of the paired cylinders is on compression or exhaust

[Joe Rappa]

If you can time it by the cam sensor on waste spark cars it will make life easier. On COP systems use the trigger for the #1 coil if it's easy to get to.

Joe

[crackerclicker]

Don't use an injector to sync your waveforms unless you have a specific reason to. You don't always know when it will turn on in the four stroke cycle, or if it will turn on multiple times.

[scottmechanics]

Cylinder compression

Hello
I would agree on the amp clamp on starter motor
Here is a you tube vid of how to set up your verus pro

https://youtube.com/watch?v=y5_yEU__RC8

Look for good repetition on a poor cylinder the compression humps are lower

[Witsend]

Look for good repetition on a poor cylinder the compression humps are lower

Nice Video, I think Snap On has the capability to put those humps of relative compression check with the amp clamp done with Verus back into the more user friendly bar graph display of the Counselor 2. It is imperative that what ever you catch shows repetition because screen was not frozen before cranking was stopped to take the photo below, so the difference in cylinder amps was not nearly as large , the next time I performed the check.

[Witsend]

I also saw a burn time graph under cylinder test menu and tried it on a 2000 Dodge Neon that had a miss at idle, but no misfire codes yet