Tachometer With Aftermarket Ecu

[pugrallye 0]

well I used to work for them, and at the time pretty much had the pug tuning market to themselves, knew there stuff too and had inside dealings with the factory

Edited June 21, 2006 by pugrallye

[TT205 42]

Thanks for the info

 

Back on topic, I asked who mapped your 8P as I don't know anyone who can do it other than Wayne Schofield in Milnrow - if the chap that worked at Coventry Peugeot Specialists is still active then it gives people on the forum more choice for mapping especially if they don't live anywhere near Manchester

 

Do you know where the chap is now that mapped yours?

 

Dave

[pugrallye 0]

Am on the case Dave, am currently looking up history of your/grahams engines and finding all the hardware which has clearly been split about six ways after ooh five years out of business

[Sam 4]

The BX coilpack clocks work fine with my omex Managed to swap that wire over today and they worked straight away!

 

It holds 2k rpm while turning over though! Strange!

[pug_ham 244 3 Cars]

I've done a few more of these now for various people & the latest one I've just done today for mark (deda205) needed very little modification to the original binnacle to get it all to fit.

 

Compare the pictures of this one below with the one I've posted above to see for yourselves.

 

All I've done to decrease the depth needed to get the new rev counter to fit into the binnacle is remove the brass nuts from between the pcb & the motor. Makes about an 1/8" difference but its enough to make a lot less cutting needed, saying that my first go above was slightly excessive. (sorry Dave, less weight though for your hill climb car )

 

I've also made a template out of one of the facias from the donor clocks so drilling the original one is less hap-hazard.

 

Graham.

[welshpug 1,651]

has anyone looked into what the difference is between the tacho heads? I was wondering if there was any way of modifying the original unit.

[madspikes 41 1 Cars]

I modified the standard GTi 8v tacho to work with my MS, it was really simple in the end.

 

mad.

[welshpug 1,651]

thats the answer I want! how did you do it? I guess what goes for MS would go for most coilpack equipped vehicles as they get signal from ECU right?

[petert 583]

Just reduce or short out, the input resistor, which suppresses the input voltage.

[madspikes 41 1 Cars]

"Just reduce or short out, the input resistor, which suppresses the input voltage." Well, thats knida what I did! What I exacly did was on a thread around somewhere.....

 

But basically I just cut a track just before the tacho enters the chip, and soldered my input wire onto there.

[welshpug 1,651]

right, thanks! i'll see what happens...

[welshpug 1,651]

"Just reduce or short out, the input resistor, which suppresses the input voltage." Well, thats knida what I did! What I exacly did was on a thread around somewhere.....

 

But basically I just cut a track just before the tacho enters the chip, and soldered my input wire onto there.

 

 

got any pictures?

[welshpug 1,651]

[welshpug 1,651]

so which is the input resistor and would this work with a motronic conversion?

[petert 583]

If you can take another picture so the tracks aren't washed out I can show you were to jump. Use a CD case to deflect the flash to the ceiling.

[welshpug 1,651]

this one good enough?

 

 

larger version here- http://i47.photobucket.com/albums/f169/wel...Ti/PICT0410.jpg

 

thanks!

[petert 583]

I'm not sure why you have two yellow wires, but one of them is the input. Under that red line is a 10Kohm resistor from memory. I just jumped where the line is with some wire. In hindsight this is probably not the best. A better solution would be to use lower value resistor as the jumper, possibly something like 1Kohm, so there is still some input protection. Those two resistors in parallel will give a net resistance of 909ohms anyhow.

[welshpug 1,651]

I'm not sure either, they both go to the same place on the PCB, Graham did mention that the input does vary in position.

 

I'll give this a go.

[welshpug 1,651]

doesnt work for this management it seems

 

checked the wire and its fine.

[petert 583]

Take a photo of the other side for me. Where are you taking the tacho feed from?

[welshpug 1,651]

err, the ecu!!

 

will take some pictures as soon as i find the battery charger DOH!

[petert 583]

err, the ecu!!

 

It could have been from the ignition module(s) or coil(s). You may need to add a pull up resistor. Just one of those things you'll have to experiment with I'm afraid.

[welshpug 1,651]

yep, the old management was Jetronic so the Signal was from the negative side of the coil, so 1 pulse for each revolution.

 

now I'm running Motronic MP3.1, theres a signal wire from the ecu.

[Guest larson]

Vote for tacho adapter instead of changing tachometers

Really easy modification. Made it yesterday to work with wasted spark coil pack, standard gti tachometer and Megasquirt ECU.

 

Based on the following Haltech scheme but used another diodes just because couldn't find 1N4004.

 

Works great and parts cost me not more than 1 GBP.

 

Here is my scheme.

 

One side was spliced into MS CPU harness (near CPU), another connected to multiplug wires inside the cabin: 112-tacho input wire and ground wire which was hanging there unused.

I have wraped all these parts together with a tape (inserted piece of pencil for strength).

Plus it's DIY adapter, you can put your name on it

[welshpug 1,651]

excellent, thank you very much!

 

is there a way of converting the signal from the ECU to what the jetronic tacho requires instead of adding more wires to the engine bay though?

 

I guess it would only be 3 short wires if I mount this on the ECU box, just use wire 112 and cut the ecu signal wire.