Emerald Ecu & Rev Counter Without Converter !

[Daz_C 8 1 Cars]

I've figured how to Run a Rev Counter without any Major Mods or Tacho Convertor using an Emerald Ecu.

The first bit is just me blabbing at how I got to where I did, so feel free to miss that bit out

The important bit is lower down and I have Successfully got a Standard Phase 1 & 2 Rev Counter to work on my car !

 

After fitting my Emerald Ecu with the Emerald Tacho Converter I had found that my tacho reads out by a massive amount at the top of the rev range (approx 1500rpm) also the tacho had a tendancy to fluctuate when driving at a steady Rpm. I found this strange as it didn't do this when it was on carbs so put it down to the Converter, I have read all of the topics on the forum concerning the coversions people have done i.e Pin1 Conversion & Signal Conversion Looms.

The Pin1 conversion was an option to try but I had a small problem that is, I have a phase 1 rev counter and it looked to have a different circuit board layout than the phase 2 so I didn't know where to start to convert it

 

After posting on another thread Pugtorque offered to send me a couple of rev counters to try, a Pin1 converted one and a Digital one to see if they worked.

Unfortunatly I had to put him up for the night in exchange for the above offer

 

Anyway roll forward 3months Lol.........

I decide to give this a crack and went about taking my instrument panel out, being a phase 1 dash it took all of 2mins and it was out !

I had 3 rev counters infront of me now ready to test/try.

• A Phase 1 Rev Counter
  
• A Phase 2 Rev Counter with the Pin 1 Conversion
  
• A Digital Converted Phase 2 Rev Counter.
  

 

I disconnected the Emerald Tacho Converter and ran a fresh wire long enough for me to work with direct from the Driver of the Emerald Ecu.

I didn't have the engine running but had the ignition on full and the Ecu set with Rpm Tell Tale so if there was any life it would show on the rev counter.

I started with the digital one as I thought if any were going to work it would be this one. Plugged the plugs together and ran the driver wire to the rev counter and nothing, not a dot I tried it across both of the 2 spare terminals and it didn't work so I moved on to the Pin1 Converted Rev Counter.....

Too my surprise that didn't work either. I checked everything was connected and I had a live, and still nothing. I was confused/gutted and worst of all back to square 1.

 

So I went technical as all us Non Electrician Electricians Do..... and I guess most of us have done this !!!!

I was armed with a Rev Counter which had a live feed - a wire with a signal feed - and a beautiful circuit board with lots of little shiny bits of solder protruding off the back Just waiting to be touched with said signal feed.

 

Note :- At this point I was baffled/confused/abit cold/pissed off/hungry/ and by now bored !!!!!

I randomly touched my signal wire across the circuit board onto different points initially with no results and then Hey Presto the Rev Counter had life I was ecstatic with joy and found a new lease of enthusiasm to get this Byatch working. I perked up and investigated further into what I had done and also tried a few different routes with the Pin1 Converted rev counter.

I then wondered if it would work with a standard rev counter so (sorry Graham) I chopped the wire on your Pin1 Coversion And it did !

So to the point of the thread - I have concluded 2 ways to make a Rev counter Work using an Emerald Ecu Without ANY need for a Tacho Converter or any other Modifications.

I have Included instruction for Pin1 Converted Rev Counters incase this Mod has already been done.

First Pic is of the Plug for the rev counter to show direction I'm working from. Which is from left to right 1-4 as your looking at it.

 

 

Phase 2 Rev Counter with Pin 1 Conversion

• 1 Live
  
• 2 Not Used - This is Originally an Earth But Isn't needed for the Rev Counter to work.
  
• 3 Not Used - This Originally is the Thick Grey Insulated Wire.
  
• 4 Not Used -
  

Tacho Driver Wire needs to be soldered to the circuit board on the right hand side of the White thing as your looking at it in the picture. Screw driver is pointing at it.

 

 

Phase 2 Rev Counter wth Pin1 Conversion Chopped

• 1 Live
  
• 2 Earth - This must be Earthed.
  
• 3 Not Used - This Originally is the Thick Grey Insulated Wire.
  
• 4 Not Used -
  

Tacho Driver Wire needs to be soldered to the circuit board on the left hand side of the Blue Thing as your looking at it in the picture. Screwdriver is pointing at it.

 

 

 

Phase 1 Rev Counter

 

• 1 Live
  
• 2 Earth - This must be Earthed.
  
• 3 Not Used
  
• 4 Signal Feed from Ecu - This had no wire in originally.
  

 

This pic is the rear view of a Phase 1 Rev Counter the plug is turned round so the Live is on the Right.

 

 

I hope this will work for other people which i'm sure it will, and also save a few quid by not having to Buy Tacho Converters etc.

[welshpug 1,626]

good work though tbh for less than a quid on resistors/diodes is it worth taking the dash apart.?

[Daz_C 8 1 Cars]

Its not a problem getting the dash off a Phase 1 which mine is, and some people (like myself) aren't that handy with soldering. Also surely its as much trouble rumaging around for wires under the dash to solder resistors/diodes into as it is to remove the Instrument panel ! Anyway that wasn't my point - my point was that there is another option.

[welshpug 1,626]

I agree with that, though I haven't touched any wires under the dash for either of my engine management conversions, both adapters reside next to the ignition amps in the engine bay

 

does the emerald create a signal like Motronic does?

[pug_ham 241 3 Cars]

does the emerald create a signal like Motronic does?

I'm not to sure what signal the Emerald creates as the Pin 1 converted rev counter didn't work on MP3.1 as we both found but one with the digital internals fitted does & also both of them work on MM8P along with Omex so its an odd one.

 

Nice work daz, even though you told a little white lie saying the wire had come off the converted one.

 

I now understand what you've done better than over the phone, you still have three wires for the tacho if I understand this right but only two of them were in the plug when we spoke.

 

Those being power & earth with the signal from the ecu going to a different point on the rev counter pcb.

 

Whatever, even if it is only saving a few £'s you've found another way to re-wire the rev counter & get it working on another system with a method thats not been done before.

 

Graham.

[16v205 9]

Good work Daz, so does the tacho keep up with the engine speed now?

 

Mine's ok if your driving at a constant speed but as soon as you accelerate quickly it lags behind. The shift lights come on at 6800 and the tacho reads 5500

[Daz_C 8 1 Cars]

even though you told a little white lie saying the wire had come off the converted one.

Graham.

 

No I didn't Graham !!!.........................It was the Digital Rev Counter the wire had come off the PCB !

 

 

so does the tacho keep up with the engine speed now ?

 

I'm not too sure yet Rich because the laptop I am using the battery is knackered so can't see any live readings whilst driving without using an extremely long extension cable

The closest I can get at the moment to find out is the Tacho Telltale and its not too bad, well 100% better than it was ! Previously with the Emerald Tacho converter, at the top of the rev range - say 7000rpm on the Telltale, the Rev counter read approx 5500rpm so the rev counter was reading around 1500rpm out ! although it was fairly accurate at tickover.

I've just been and checked now and the Telltale reads 6556rpm and the revcounter is reading just over 6250rpm. So from that point of view its alot better.

But in all honesty I'm guessing nothing you do with these rev counters is going to get it much better than that.

[M_R_205 5 1 Cars]

great topic! just wired my emerald up the same way but on my rev counter (out of a 309 i think) the white and blue things are replaced with two orange things, but it still worked the same!

 

as for being acurate on tick over its about 150-200rpm higher than the laptop and this stays the same up therev range, though i dont realy care lol

 

Paul.

[Tom Fenton 1,526]

Hmm, I'm confused now. I have been battling trying to get my rev counter to work, but mine doesn't look like either of the ones in the pictures above. Does anyone know the method of driving the standard rev counter from a wasted spark coilpack inputs?

[RossD 43]

Haha, thats exactly how I got my Emerald to talk to the rev counter - Took the feed and tried all the feeds\pins until it did something. I think I've probably even connected it to the same pin as you.

 

Seems accurate enough to me (About 150rpm out at the top end) and doesnt lag behind.

[pug_ham 241 3 Cars]

Does anyone know the method of driving the standard rev counter from a wasted spark coilpack inputs?

I've got one here that was wired to pin 1 of the chip that worked from the ecu signal off an MM8P ecu, doesn't your ecu send the rpm signal?

 

Graham.

[taylorspug 7]

great topic! just wired my emerald up the same way but on my rev counter (out of a 309 i think) the white and blue things are replaced with two orange things, but it still worked the same!

 

as for being acurate on tick over its about 150-200rpm higher than the laptop and this stays the same up therev range, though i dont realy care lol

 

Paul.

 

If its the same the whole way through the rev range just take the needle off and re-position it.