Labscope Relative Compression Question

[Woefman]

I love your videos. My Favorite is your Geeky Relative Compression Video.

I have all the tools you used.

My question is on channel 2 how did you hook up the scope to the coil? The video is not clear to me on wheather a second amp clamp was used.

Thanks So Much in Adavance.

[Woefman]

update …. The scope has ability to do amps (10 amps max) using the pos+ and neg- leads

so i was wondering if you did ch2 that way or do you have 2 amp clamps

maybe i should watch video again….ive watched it twice but on a stupid small screen(phone)

Thanks

[Woefman]

Hello is this thing on????

I find it funny, people post they need help with a car yet leave out important info i.e. Year Make Model and then some. And replies like crazy to those posts.

I have legit question (video camera not pick up how connected ) and I get no response.

[Aquaman53]

Wolfman, he clipped the amp probe around the positive battery cable, at the battery. When placed around the battery cable, the clamp has to be completely closed. There should also be an arrow on the clamp indicating the direction of the flow of current from the battey.

[Aquaman53]

Woefman, he clipped the amp probe around the positive battery cable, at the battery. When placed around the battery cable, the clamp has to be completely closed. There should also be an arrow on the clamp indicating the direction of the flow of current from the battey.

[dennis524]

I think Woefman was asking about what he used to identify which plug was firing to identify the
faulty cylinder using the firing order.
I have the same question.

[Apex]

You can use cylinder #1 COP or fuel injector on channel 2 as your identifier to determine which cylinder is your #1 cylinder, then count the compression events by firing order to determine the remaining cylinder numbers. There’s probably a lot more ways to do this.

I would probably simply use an inductive pickup over the COP (I believe this is how Matt did it), but if you have a DIS or distributor you could probably put a second clamp on the plug wire.

[Arthurmax01]

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[Georgesauto]

You also can use the trigger signal sent to the coil on plug using another channel but note : if its a 2 wire COP then you need to have an attenuator in series with your scope channel to prevent damage to your scope . If the COP has more than 3 wires then you need to connect to the signal wire that has a square wave signal. Check wiring diagrams for the cop set up. The falling edge of the square wave is when the coil fires. I would avoid using a amp clamp as it can show multiple coil current draws at the same time for this particular test as it can mislead you regarding the firing order.

[Georgesauto]

You also can use the trigger signal sent to the coil on plug using another channel but note : if its a 2 wire COP then you need to have an attenuator in series with your scope channel to prevent damage to your scope . If the COP has more than 3 wires then you need to connect to the signal wire that has a square wave signal. Check wiring diagrams for the cop set up. The falling edge of the square wave is when the coil fires.you then need to verify the firing order of the vehicle using factory info.

[Author]

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