Question about engine data communications

[fish80]

I have the engine data cable going from my ETEC to my lowrance graphs that show my rpm, trim %, load, voltage, etc. My problem is that the rpm's shown on my graph are about 400-500 lower than the rpm's shown on my ranger analog guage in the console. Which one should I trust to be correct? Thanks

[1BADAIR]

Analog is rarely accurate

[BRNut]

Agree with 1Badair,

Data coming from NEMA network, no analog conversion.

I am guessing that at idle your graph is showing about 1000 or a bit lower.

Now if you graph is showing 400-500 at idle.........

[fish80]

I haven't paid attention to the idle rpm really but i think it does idle in neutral at about 500 rpm. Just noticing at WOT my graph is showing about 5800ish and my analog is showing almost 6500.

[BRNut]

Evening Fish,

I think ETEC idle is about 1100, best guess. Seems like I read somewhere that there's no adjustment for the newer ETEC's they are computer controlled.

Analog gauges and there subsequent calibration have zero settings and span (high end) settings.

I would tend to believe the engine data on the graph, even if both seem to agree toward the lower end of the scale on the analog gauge.

Best,

BRNut


Note; after 9pm I apologize for bad spelling and grammar......

[GarryW]

The Evinrudes that I have had idle around 500 rpm and max out well below 6100 rpm. I would suspect that your analog gauge is off. The data coming on the NMEA bus interface comes straight from the EMM so it is pretty accurate.