To get my Rev Counter working along side the RPM input on my AVC-R I have had to run a wire direct from my Rev Counter to both coil pack earths (bridging them), as far as I can tell this will mean all 4 plugs spark all of the time.
Normally it would only spark 2 wasting 1, but now it will be sparking 4 and wasting 3.
I just wanted to know if for any reason this would be a problem for the engine aside from wearing out the coils and plugs quicker which is negligible? Is there a chance it could ignite the gasses on the intake stroke or must they be compressed before thats possible?

It runs fine but any input is as always, welcome!

 

didnt bridge anyting on my s2 when it was coil pack on dta, jus ran a single wire from the centre pin on the coil pack to the input on the rev counter

 

hmmmm.... i want my rev counter working. u remember how u done it? ive got efi clocks ? u get it working and....

 

how do u know what one's the feed?

 

it was a while ago aron , but gaz showed me how to to it, if i remember it was the centre pin and the two outers are earths and it switches between the two if you know what i mean

 

next time ur around ill show u my clocks and see if you remember! ive asked this question on here loads someone said something about an amp?

 

Oh! The centre pin is the live feed and the rev counter uses a earth signal........... but i'll go outside now and try it!

 

EFI clocks use a low voltage input not a high volt setup like MFI clocks so wont run direct from the coil!

 

can u not get a RPM signal from the ECU?normally run it from either side of the coil pack,

 

Yeah I can Carl but it's running my AVC-R, if I try and use it with my rev counter as well the AVC-R shows about 6000rpm at idle! lol!

Just tried the centre pin to the rev counter and that doesnt do anything at all!

But no need to worry now as I have this handy diagram to show me what I need to do!

 

bit late here, but no you can't run the two wires from the coil pack, you muct use the setup like in the diagram you've found.
the 1N4004 diodes can be bought from Maplins for a few pennies, the zener one isn't one they stock, you'll have to find a substitute one that they do sell, check on their online shop to identify one they do sell.
i bought what i needed for around 69p, lost the parts now so have to do the same again.

 

lol Yeah
Got it all from Rapid Electronics though, so jobs a good un!

 

ahhh, good call, i'll try them and get mine ordered, it's a pain having to just use megatune to see what is going on.

 

Well my AVC-R shows me but i want my rev counter working too!!

 

The finished item..........





Works ok.... but the rev counter hangs and fall back jerkily rather than smooth like it did when I had it running off the coil pack with out the diodes inline

 

Try wiring your AVCR to the coil packs, and the rev counter to the tacho output on the ECU. Or, feed them both from the ECU with a 1k resistor inline to the AVCR.

Rick.

 

The ECU will not run the Tacho direct, it's a low voltage output.
I could try the AVC-R to the coil pack although it will need to go through the above Diode setup too.

 

Actually, thinking about it - run the avcr straight of ONE of the coil neg's and set it to 2 cylinders. Then use a 2N5551 or similar transistor to drive the tacho.

Rick

 

Ah now that is a good idea!!
How do I wire the tranny in, i'm asuming it works like using a relay to create a hi volt spike?

 

Bit more involved, you need to open the case and feed the transistor from whichever point you assign in the software as the tach output.

 

Oh ok, i'll just use a realy as in this diagram.......



Easier!

 

that won't work without the transistor to turn on the relay. You'll cook the CPU if you connect it direct...

 

The ECU has a dedicated tacho output, that is the wiring diagram provided by the guy who built the MS ECU to run HiVolt tacho's!! lol

 

In that case you're sorted