Looks like the ecu triggered tacho signal is not good for my VDO tacho (EJ20T to Porsche 914). It was run as per standard setup from the coil on the old Subaru engine (EA82T).
Any electronic gurus out there can solve my problem? Signal strength? amplified? little do-dads?
:alien

Hi Pete

Call Barry at St George Instrument Services Pty Ltd
91 Planthurst Rd Carlton NSW 2218
ph: (02) 9547 0855
he converted my tacho to work with electronic ignition.

1302Steve

Great stuff Steve thanks, I'm on to it tomorrow!
I love this site.:thumb

For an easy ( answer that will cost maybe $2, have a look at:

http://autos.groups.yahoo.com/group/subaruvanagon/files/Wiring%20/ 
And then download TachWiringDiagram.jpg.

This worked for me with EJ22 in a Transporter and Transporter Tach . . same system for 6 cyl, but another diode for the third pair of HT signals.

Dave

love to see this wiring diagram. I have an EJ25 in a J&S buggy and the speco tach I have is not working either. However, I am not a member (you need to be to access the file), and the group only allows membership to those putting subies in kombis. :repuke
Could you please upload the diagram onto the forum for us.

Barry was not much help, but a friend sent me this for a Nissan so I'm going to try it. It should work. Just passed on to Barry at St George and he has many uses for it........!
Just use 1/3rd of the circuit.


[Edited on 7-6-2004 by speedster356]

Thanx for the diagram. Looks really simple to make.
Got some questions about the diagram though.

What sort of engine is the diagram for?
It looks like a V6 with a waste spark set up.
Is that correct?
Is it meant to have one pulse per coil pack or what?

I have an EJ25, would I set it up with two of the units (instead of the three in the diagram), that is, one per coil pack?

Sorry, Couldn't work out how to include a file. . Here is the two diode method from the Vanagon list.

Incidentally, there is no difficulty in joining the group .. and there is a huge quantity of material there in files, photos and the forum itself

Dave

Thanx heaps man! :kiss

The tacho was only showing half the RPM until we changed the switch from 8 Cyls to 4 Cyls. (ok, maybe we were being optimistic)
Now it works like a treat, :thumb

Thanx guys

the tacho is only reading 4200rpm when the engine is bouncing off the rev limiter. Kinda weird. Any ideas?:o

Did you ever work out why Pete?

Just my 2 cents worth.

I did a ej20t into my notch about 6 years ago and it plugged straight up to the factory ecu and worked fine.
What was it?
Autometer Sport Comp.

needs a bump , this should not be lost can we put it on file some place ?

Bump for Jenny

Hi Neil,
for the two diodes used in the circuit posted by Transparu you should be able to use something like 1N4004, rated at 1A/400V and only about $0.10 each from Dick Smith or Jaycar or Radio Spares, etc. Just make sure when you splice/solder it into the line that you have the end with the band around it pointing in the direction of the arrow in the circuit (towards the tacho in this case) and make sure you use heatshrink or other waterproof insulation over the joins and diodes so it can't short out.

for hellbus

I read this and it hurts my head. I can make anything out of steel, bolts and welds, but this stuff bows my mind. I will just take a printout of the diagram and my tacho to a whizz bang geeko electronics guy I know.

I need one as well it would cost like $0.25 for the bits

I tryed this set up to night on my ej20 quad cam > it did not work :cry:cry:cry:cry:cry:cry:cry:cry:cry:cry:cry:cry:cry:cry:cry:cry:cry:cry:cry:cry:cry:cry

Oh dear, the only thing I can suggest is that you double check your connections because it should work. Have you confirmed that your loom's wiring agrees with the diargam eg yellow/red & red/green go to coil for 1&2 with blue & red/green going to coil for 3&4? If they are as per the diagram above then are you sure you have the correct connections at the tacho? If you're positive you have everything wired correctly then you could try some experimenting, eg disconnect the diode from the blue wire and connect it to the yellow/red wire to see if it makes any difference.
If all else fails, drink more beer...and you may see the light.

My ignitor has more wires than the three shown > the coil pack on my motor has three wires of these one is earth how can I go wrong ?

nope dont work ! :jesus:jesus:jesus:jesus:jesus:jesus:jesus:jesus:jesus:jesus:jesus:jesus:jesus:jesus:jesus:alien

I sort of look just like that now !

were is some were high so I can jump off !

I have now connected ( one ) wire the rpm is working but not to full rpm .If I connect the other wire the rpm on the gauge goes to 0.
so what in hells name is going on now ?
the dip switches on the vdo gauge are correct .

Start doing some continuity testing. Make sure you don't have a bad connection somewhere, easy to overlook.

yep on that , I check the connectors , cheers

In the abaove diagram the red/green wire on the coil pack is 'common' but this does not necesarily mean it is at earth potential.

I have had it with this ecu and just about to pull it out and run it over with my 4x4 its a pain in the ass !