Standalone ecu, aftermarket rev counter

[pork]

I need my rev counter to work (shift light controls supercharger clutch)

Ever since I've fitted injection and ecu, the rev counter don't work

Any suggestions?

Any way off testing whether I'm actually getting signal from the ecu?

[andyborris]

Which ECU?

On many you can use one of the unassigned outputs for this.

[pork]

It's a redline developments ecu (kdfi)

I'm using the dedicated rev counter output, it's all enabled on the software too

[pork]

So is there a couple of tests I can do?

[welshpug]

was the original rev counter triggered from a single coil? and its now running a waster spark coil?

[pork]

Yeah, was on carbed engine, single coil

Now coil pack ignition

[welshpug]

I made a thing for my 205 and a mates 205 that picks up the ecu's earthing signals to the coil and sends it to the original tacho, I have enough bits here to make many more.

[pork]

Ideally I'd like to use the tach output with the ecu

So just need to test to see if output actually works

[welshpug]

my mate is using a DTA ecu and myself a Bosch motronic, there wasn't any other way to do it other than get a speedo head from a newer car that will accept the signal.

[RobinJI]

Have a read in here: retrorides.proboards.com/thread/142841/1972-lancia-fulvia-coupe-megasquirtin?page=46

There's a discussion of 2 different circuits you should be able to use to get the rev counter accepting the signal from the ECU.

[andyborris]

If it's a aftermarket tacho (and it sounds like it is, because of the shift light), you may need to change it's settings. If you're using a wasted spark set up, the tacho may be seeing too many signals.

If you can't reset the tacho, then maybe a filter circuit is needed as above.

And on some ECUs, you can configure a output to switch at a certain rev limit and use this to drive the supercharger clutch.

[pork]

The relay coil one looks ok to me

Is it just rhe coil from an ordinary 5 pin relay?

[vitesseefi]

Yes, worked for me. I had to mess around with the circuit a bit and try a different value zener diode but it did the trick in the end. That was with an old Smiths RVC tacho in a Triumph.

Nick

[pork]

Cool

So a trip to maplins tomorrow

So need a:

5 pin relay
Transistor
1k resistor

That right?

[carat 3.6]

You need this: www.emeraldm3d.com/accessories/tacho-driver.html

[RobinJI]

May 8, 2014 21:29:19 GMT pork said:

Cool

So a trip to maplins tomorrow

So need a:

5 pin relay
Transistor
1k resistor

That right?

Looks like it. Let us know how you get on. I'm kind of interested as I've got a nice smiths rev-counter spare that I'm debating using in the MX-5. Hence why I rememberd that post in the Lancia thread. (Well, that and the Lancia thread being in my bookmarks because it's a good read.)

[pork]

All sorted now..."............turns out the ecu outputs were back to front in the instruction booklet!!