Rev counter not working with emerald

[Dave McCulloch]

A relatively small problem at the moment, given the woes of my 1900K, but the rev counter is not working with the emerald. The old engine and loom was distributor based and hence fed the single ignition wire to both the coil and the tacho - tacho worked fine with the MEMS and also with the emerald.

 

New engine is wasted spark and hence emerald is set up in Twin ignition output mode. When I made up the new loom, I ran a wire from pin 12 of emerald to the tacho. I have checked the continuity of this wire from the emerald connector to the connector on the back of the tacho - resistance is less than 1 ohm. However, since installing this engine/loom, the tacho hasn't worked at all.

 

The emerald was sourced secondhand. I have installed the latest software v1.1 r7. Myles had suggested disabling "Tacho Telltale", but in the version I have this option seems to be greyed out and not selectable in any case. "RPM Events" is NOT selected (though I've no idea what this is anyway ).

 

What else should I check before assuming a fault within the emerald, and sending it off for checking/repair 🤔

 

Dave

[Myles]

Dave - you *have* tried changing these settings with the unit powered-up, haven't you? A number of setting can only be changed when the whole thing is plugged into the laptop (i.e. they are not stored in the mapfile).

 

Project Scope-Creep is live...

 

Alcester Racing 7's Equipe - 🙆🏻™

 

Alcester-Racing-Sevens.com

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[nutty7]

 

Dave, which type of tacho do you have, i might be way off here but it could be worth a try, on my caerbort tacho on the back if you remove the grommet there's 6 switches if switch 4 is off try it switched on

 

wot another package!

[Dave McCulloch]

Myles - Two things confirm the ECU does think it's in Twin ignition mode - 1) when I connect the laptop to the ECU, I "read" the map from the ecu, rather than picking it up from the hard disk, and 2) I have had all 4 plugs hooked up to coils outside engine and all 4 are sparking.

 

Paul - the tacho worked fine with the old engine and wiring loom, so I see no reason why it should not be working now. As I've checked the integrity of the wiring from the ecu, the only other thing I can see affecting it is either an ECU setting, or an ECU fault.

 

Dave

[mav]

Dave,

 

Paul is suggesting you check the settings on the ECU, if it is configurable. If it is, and you were not wasted spark previously, then you may need to chage a setting?

[Dave McCulloch]

Mav

 

Unless I've completely misunderstood, I thought Paul was saying there are switches on the back of the tacho? Since the tacho worked before, and it should still be receiving a similar signal type and frequency from the newly fitted emerald, I can't see it should need any changes? Or have I missed the point?

 

Dave

[mav]

I'd check anyway, but of course, I may be completely wrong.