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G3X touch IGN timing display

jacksel

Well Known Member
I was hoping someone might be able to help me with a problem I'm having with my timing display on my new RV-6 panel. It seems to read backwards. i.e. 28 deg at TO and 25 deg at cruise. I have the timing interfaced to my G3X touch display with the L2e unit. Since there is only one signal wire (pin#3 of the output connector, Plasma 3), it seems to me there's no way of getting the signal reversed. The only other possibility I could think of was reversed calibration settings on the display unit but that checked out good. It also reads accurately at 0 RPM (0 deg). The static voltage and ground on the unit checks out at +5v. Has anyone ever seen this problem? The timing display was working fine with the old LCD module so I would say that eliminates the output connector.
The folks at Flight Data Systems are as puzzled as me. I'd really be interested in any thoughts on this.

John (Jacksel) Walsh
83FL, Yulee FL
 
I was hoping someone might be able to help me with a problem I'm having with my timing display on my new RV-6 panel. It seems to read backwards. i.e. 28 deg at TO and 25 deg at cruise. I have the timing interfaced to my G3X touch display with the L2e unit. Since there is only one signal wire (pin#3 of the output connector, Plasma 3), it seems to me there's no way of getting the signal reversed. The only other possibility I could think of was reversed calibration settings on the display unit but that checked out good. It also reads accurately at 0 RPM (0 deg). The static voltage and ground on the unit checks out at +5v. Has anyone ever seen this problem? The timing display was working fine with the old LCD module so I would say that eliminates the output connector.
The folks at Flight Data Systems are as puzzled as me. I'd really be interested in any thoughts on this.

John (Jacksel) Walsh
83FL, Yulee FL

John,

What are you seeing at idle? According to LSE, you should see ~35 degs or ~40 degs at sea level depending on your engine.

LSE Timing Values for Plasma CDI:
Engines Normally Timed at 25 degrees BTDC:
These are usually engines with compression ratios less than 8.7:1.
At idle the strobe light should indicate 40º ± 2º when the manifold pressure hose is connected and 21º ± 2º when disconnected.

Engines Normally Timed at 20 degrees BTDC:
These are usually engines with compression ratios of 8.7:1 or higher.
The timing is retarded another 5 degrees. This setting should show idle strobe light readings of 35º ± 2º when the manifold pressure hose is connected and 16º ± 2º when disconnected.

You can verify the output of the L2e signal conditioning module with a multimeter on the ground with the engine idling. As you know, 35 degs should be 3.5 Vdc and 40 degs should be 4.0 Vdc at the output of the L2e.

Steve
 
I think you may be looking for 0.35 volts at 35 degrees, not 3.5 volts. My Lightspeed manual indicates 0.01 volts per degree.

Regards,
Rob
 
I think you may be looking for 0.35 volts at 35 degrees, not 3.5 volts. My Lightspeed manual indicates 0.01 volts per degree.

Regards,
Rob

Negative. John is interfaced to the L2e signal conditioning module, not the Lightspeed ignition.

According to the L2e manual, the output is 0.1 V/deg.

L2e Output.jpg

Steve
 
Last edited:
Ah - understood. I should have picked that up. Sorry for any confusion I may have created.

Regards,
Rob
 
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