Relative compression testing using an amp probe and a verus

Testing an engines relative compression using an amp probe and a Verus lab scope. The engine is a Chevy 5.3 with the number 3 cylinder spark plug removed to show what a low compression cylinder looks like when doing a relative compression test.

Category:

People & Blogs

Tags:

• MOV02594

[phils57]

Good job! If you add a second trace connected to number 1 ignition primary or secondary and trigger on that trace, you would be able to tell which cylinder had the low compression. this assumes you have disabled the fuel system to prevent starting and not the spark.

[maycor1076]

If you remove a spark plug and do this test it would also show a missing hump. I have seen where spark plug threat got damaged and leaked pressure also in that case you could have a missing hump. Another thing you can do to know which cylinder is the one at fault is by hooking another lead to coil/wire. This way you can tell which cylinder is at fault. Good post

[DoctorD907]

Thanks you for the great info! Very informative.

[Jakepayne99]

Nice Dr.GreasyboB.............