REV COUNTER issue for 1.8t

Hi,

i use mk4 golf ECU for 1.8t setup after canceled immo. i want to use mk1 golf clocks. i connect oil lamp, charge lamp, water temp without any problem, but i can't connect mk1 rev counter. i have found RPM signal cable in Mk4 ecu which is green but it doesn't work when i connect it to mk1 clocks. :dontknow:
any idea?

thanks…

need a signal converter, the 1.8t signal is not compatible with the clocks. MK1 has same signal as MK2 if that helps you track down a converter

rubjonny said

need a signal converter, the 1.8t signal is not compatible with the clocks. MK1 has same signal as MK2 if that helps you track down a converter

Thanks Jonny,

where can i find this converter? or is there any other solution?

erm i think qpeng do them?

You need 4 1N4004 diodes and a 18V zener diode.  

Connect a 1n4004 to the trigger wire from the ecu of each coil.

that doesnt work for oem 1.8t

Fair enough.  Was going to look into running that at some point but now i'm gonna be running megasquirt so will be using a signal from the megasquirt mainboard, i think, maybe, possibly, when i get the damn car finished!

yeah you need the 4 in4004a adaptor circuit as above for a megasquirt ecu i think, pretty sure the ms rev signal is different to mk1/2?

the reason it wont work on the oem ecu is the signals used to trigger the coils are different

I'm using OEM COP so would have the same problem in using that, was looking through my megasquirt build last night (been a while since I built it!) and the OEM COP use a 5V trigger signal which is why they won't work with that setup above.  The MS ECU can supply its own rev signal, there are a couple of options for use with triggered rev counters, not done it yet but shouldn't be too tricky I hope.

yeah its +ve on the cop and you need -ve for the in4004.  if ms signal is -ve for the revo iirc there was a simple circuit you can make up to make it work on the ms?  was on cgti somewhere

oh god, thanks for this discussion mates…
but, i m still  confused :dontknow:

simple answer, oem ecu = buy a rev counter adaptor

rubjonny said

simple answer, oem ecu = buy a rev counter adaptor

Thats very simple John

Where can i find this adaptor?
Qpeng don't respond me.

let me do some forum digging...

jabbasport do one as well apparently, ad some more info I just dug up:
http://www.clubgti.co.uk/forum/showthread.php?t=227651

rubjonny said

jabbasport do one as well apparently, ad some more info I just dug up:
http://www.clubgti.co.uk/forum/showthread.php?t=227651

Thank you so much John. i m gonna try it

Bumping this for some more info if anyone has it.

I'm going to make my own hopefully so just need clarifying a few things.

a) Diode is used to convert the AC Signal into DC
b) Transformer/Transmitter is used to Change the Output Voltage to accomodate the Mk1 Clocks Rev Counter

Ok Quesiton time  

1) Anyone know what voltage/frequency the orginal clocks operated at or its repsective values? Im assuming the MK4 Output from the ECU is 5v and we are requiring 12v?

2) Are Resistors needed, as its been said they are for the MS application (Running Wires inline with resisitors to the Diode from the -ve on the coilpack) I am using OEM

FYI - Qpeng only sell the Converters as part of their loom kit… Have Contacted Jabbasport three times and had no such luck sourcing one.

There is a company in america that wants $150, surely the parts are like 10?

Many thanks
Gary

the agu ecu sends a -ve signal to the coilpacks i think, so in theory you can do the diode trick on them same as you can with megasquirt wasted spark. though you'll need 4 diodes 1 for each coilpack. this is only a theory ive been working on, im not 100% sure if it will work

Need to wake this thread up as I've been asked to build a converter for some northern monkey's 1.8t converted MK1 revcounter.

Anybody actually know what the signal is from the ECU, some speculation that it's a negative signal, which seems very odd - anyone know it's frequency relative to engine speed?

its a low ampage signal thats the issue, pretty sure its still a -ve pulse? the mk1/2 clocks expect a full 12v switched -ve as you find on the -ve terminal of the coil see so the low amp signal on the ecu is not strong enough. if its any help the mk3 ecu signal is the same?

you can get adaptors from several places so it would have to be cheap for it to be worth your trouble!
http://www.edition38.com/forums/index.php?showtopic=440379