As above really. Need it working. I know mk4 efi clocks worked but I have a mk3 now so no good :-(

 

There's a sticky in this forum about efi conversions

Should be in there

 

What loom have you used

 

Xr3i loom and has fiesta RS engine ofab loom mate

 

im not sure about mk3 clocks but i used a wire straight from pin11 on the edis to the rev counter on s2 mfi clocks and it works fine

 

Or you can use rs1600i clocks.

 

How sure are you on the 1600i clocks? and cheers Lauren but already tried all that as used to have this setup in my mk4 using efi clocks but as its a mk3 now the dials have gone :-(

 

Laren is correct. Run a wire from pin 11 of the EDIS to the green rev counter wire, this will give you a clean tacho output that you can use with your S1 dials. The EFi dials take the output of one coil drives (usually pin 10). You do not need new dials!

FYI, pin 11 is missing from the usual Ford EDIS harness.

Lee

 

I've tried using pin 11 but no good, it worked fine before on efi clocks but not these mk3 clocks :-(

 

Pin 11 won't work on EFi clocks, it will read double the revs. You have to use pin 10 for EFi clocks. Did you add a new pin to the connector for it? I'd say check the contact and continuity to pin 11 as that will give you the correct reading you require.

Lee

 

Ok I'll have to have a look mate cheers I'm sure I used 11 as it was the only blank one and it worked fine lol but ill let you know bud cheers

 

second pin in on the edis a green and yellow wire ,straight to the clocks ,works on my fez

 

What fiesta mfi or efi? Cheers

 

Pin 2 and 11 are the same output and are the ford IDM out. The output was used for most ford efi rev counters, I didn't know pin 10 was used for efi clocks? can you confirm this Lee as it would be handy to know.

You have a few options, if you can't get it to work with pin 2/11 on the EDIS unit you can use two two diodes and a resistor for the coil outputs. This is how the clocks on my car work.

Your other option is to connect a relay coil inline with PIN 11 on the EDIS unit. The IDM signal is a 12v square wave, it pulses on the ignition coil flyback, adding a relay coil inline will create a high(er) voltage flyback than 12v which is what none efi clocks like to see, ie clocks that were originally triggered directly from the ignition coil, were mk3 clocks connected to the negative terminal of the coil?

Goodluck and let me know if you need more info.

Rob,

 

Flip the connector around, it'll be pin 11 of 12 not pin 2 that's diagnostics.

Pin 2 and 11 are not the same output. Pin 2 is IDM (Diagnostics signal) as you say.

Pin 11 is Clean Tacho Out not IDM. It's a combination signal of both coil drives (same as your diode circuit) and can be used with standard RPM gauges.

EFi clocks use pin 10 for their RPM signal, which is one of the coil drive outputs (Hence why it only reads half the revs on non-EFi clocks).

Here's a cracking little document on Ford EDIS for those of you that are interested: http://www.dainst.com/info/edis/edis.html

Edit: Just to clarify, by EFi clocks I mean clocks that originally came from a car fitted with EFi from the factory (XR3i EFi, Fiesta RST etc.)

Lee

 

Cool cheers Lee, pin11 and 2 are the same output. They are connected together via a track on top of the ceramic pcb, ill double check this when I get in. Cars using the IDM as a tach signal usually have a small box inline with the tacho, this filters out the small pulse the IDM gives when there is no coil output.


EDIT**
Just had a look at the document you linked and that says the same about the IDM signal with a filter inline with tach. So the FRST uses pin10 and not 2 as standard?, its a pain trying to find out which cars use what. Most American cars seem to use the IDM to drive the tacho and I assumed the fiesta RS would be the same. Would be good to know as im including a tach out with a board im doing at the moment.

Rob,

 

Interesting, I read that as just the ECU gets its tach reading from the IDM. That document makes no reference to pin 11 other than in the Pinouts. It's interesting that you say pin 2 and 11 are connected together since the 64us pulse needs filtering, which would make the tach output dirty, not clean.

Browsing through so many other threads and guides, pin 2 is cut back on and FRST setup as its not used by OFAB and OFAC, apparently it's cut back from the factory on an FRST.

You're right about it not being easy to find this stuff out. But it seems that European Fords don't follow the same setup as the American Fords. I know I read that the FRST uses pin 10 and I'm sure the XR3i EFi and XR2i do too, I'll see if I can find it

Lee

 

Awesome, thanks Lee.

64uS is a very narrow pulse, and although ford filters it I doubt any stock rev counter would be fast enough to respond to it. The FRST revcounter I tested only responds to pulses longer than roughly 400uS, but will occasionally 'tick' on the narrow pulse. The 64uS pulse vanishes as soon as there a flyback voltage from each coil so I guess that it is clean whilst the car is running. The IDM pulsing only on coil flyback pulse is useful for tracking misfires down too which is handy.

I don't think any ford ecu (EEC-IV on) used extra tach inputs other than crank/cam/PIP so i guess they are referring to using it as a rev counter driver. I've got some vague recollection of there being some tacho conditioner that plugs into the loom on some cars???? But that might just be rubbish.

Using only Pin10 to drive the tacho makes my life soooo much simpler, so thanks very much for the info

PS,

I think pin 2 and 11 being connected is probably a legacy thing, I suspect they had a pin left over on the EDIS4 unit so though fuck it, I'll use it for this.... I doubt the EDIS6/8 has the IDM output on more than one pin.

 

Don't take my word as gospel Rob, I'll try and find out 100% first. My car is 200 miles away though unfortunately so I can't pop out to take a peek! I must have read/observed it as I wrote it in the sticky. Can't believe it was 4 years ago I refurbished my XR3i EFi loom, so I'm a little rusty!

Lee

 

Haha, no worries. If I find out anything interesting I'll let you know!

Rob,