rev counter input?

[gunni]

That really leaves you few options but to get an oscilloscope on the current tacho wire to make sure it´s actually working.

[Tony C]

getting hold of an oscilloscope is the next problem,

the wiring has not changed from running the coil set up,
had a mallory cdi unit which had a tach output,
when this was removed the tach wire was moved from the cdi straight to the ec36 vems plug,
weird aint it,

[Tony C]

i have a test meter with rpm on it,
if i connect this to the tach output wire from the vems would that give us an idea if its working?

[gunni]

Only if you have the 12v and resistor on the circuit.

Can you measure continuity from the vems tacho output to the tacho?

[Tony C]

i'll do that after work tomorrow,
cheers guys.

[paul_f]

My tach worked fine with the Mallory CDI box.

I then plugged it straight into points and it didn't work.  It didn't work when i connected it the Vems either.

I have just sent it to Autometer and they said there was a resistor fault and it is fixed now.  It cost 25 dollars plus shipping.  I would have tried to fix it myself, but I couldn't work out how to remove the front rim without damaging it.

I wonder if the mallory CDI damaged both of our tachs?

[Tony C]

let me know if it works when you plug it in this time mate,

i may have a go at taking mine apart,
in the long run i want to use the o/e capri/rover hybrid rev counter in the dash,
as it looks factory,
and use the shift light from my autometer rev counter and let vems control them both,

[dnb]

I wonder if there simply isn't enough drive current from the P259.  350mA isn't exactly a lot...  You have 6 IGBT channels, so there are 2 spare after the coils.  You could try a spare one of these - they can deliver a lot of current.

I wrote on the case the IGBT channels that aren't populated to give you a clue. 

[Tony C]

checked ch0 as requested, no 12V when its set too 100 and p259
checked contu from vems back to tacho and alls fine,
will give the resisitor another go the weekend,
whats should i be looking for on the divider?

[Tony C]

I wonder if there simply isn't enough drive current from the P259.  350mA isn't exactly a lot...  You have 6 IGBT channels, so there are 2 spare after the coils.  You could try a spare one of these - they can deliver a lot of current.

I wrote on the case the IGBT channels that aren't populated to give you a clue. 

ah rite,
will have look when its light, maybe weekend now mate,
will i still need to use the pull up resisitor?

[dnb]

The ignition channels are called I259.  They are selected in the same way as you would a p259 channel.
You will need a pullup resistor.

[Tony C]

still no joy,
the car was at the alarm specialists today also,
it has a CAT1 clifford alarm fitted with intelli start,
this runs on ANY set up as it just needs to detect a varying voltage to arm the remote start,
even the clifford could not detect any rpm output from the ecu,

any ideas?

[gunni]

Has the ecu been tested by somebody else?

[Tony C]

Dave (dnb) repaired the trigger prob for me,
not sure if he tested the tach output though,
Maybe Dave could reply,  ;)

[paul_f]

let me know if it works when you plug it in this time mate,

i may have a go at taking mine apart,

I got mine back today.  I'd definately try and open it yourself, Autometer charged me 25$ for fixing and cleaning it but 75$ to post it back! It only cost £7.20 to send it there

Still it is cheaper than getting a new one.

I'll let you know if it works now!  I fitted a pull up resistor inside my ECU, it didn't have one originally (although the pads are there)