haltech tacho

[cri_ag]

hi all,
ive just got my 4agte (twin coils, wasted spark, stock tacho) running in my sprinter, but im unsure what to do about the tacho. i searched and no one seems to run them off the haltech tacho output? i assume this option doesnt work. i remember seeing a haltech diagram involving twin coils, two diodes and a couple of other fancy looking symbols, but alas i cant find this anywhere on the haltech site. so in short, how do i make the tacho work?

[TA22-3SGTE]

Hi
Run the tacho of the tacho output from haltech , I 'v used the tacho output to run the tacho in all my instalations .

Trevor

[cri_ag]

Hi
Run the tacho of the tacho output from haltech , I 'v used the tacho output to run the tacho in all my instalations .

Trevor

yea? even for a car that came with a coil and dizzy arangement?

[Hen]

All in here

Circuits you can use are:
From coilpacks - what I'd recommend, you'd just use 2 inputs, not 4 though.
Or from ECU output - Also works

Hen

[takai]

If you are running a Haltech E6 (i assume the others too) the tacho output wil run pretty much anything fine. Im running my Autometer 5" tacho (fully dose bro) off it fine.

[Hen]

...the tacho output wil run pretty much anything fine...

Anything that needs a 12V square wave signal. And this doesn't include stock Sprinter tachos.

[takai]

My E6x has an option for square wave or rising signal...
But the diagrams which you posted will convert it across anwyay.

[Hen]

My E6x has an option for square wave or rising signal

That's very nice of Haltech, I never knew any management did that.

[lojik]

Takai, I have an E6X, I've never seen that option. Where will I find it?

[cri_ag]

whats the bet the square wave/rising edge option is not available on the e6k!

cheers so far guys, especialy to hen for that awsome write up!

[cri_ag]

just to let anyone else know, i used hens method of pairing the two coil packs together to give one signal. worked a treat! and it cost a grand total of $1.18 its easy two, even the electronicaly retarded can do it (me). thanks hen.

[cri_ag]

just a bit of an update on this, ive been having a bit of a problem with a very light misfire on my 4agte. i think ive traced it to this tacho wiring, is it posible i need bigger diodes or something? the misfire seems to go when this circut is disconnected.

[sideshow]

ive had this problem too on a 4g63 with twin coils

i ran 2 big doides of the coil triggers
and it missed up hi rpm

u might need to get a tacho booster
then run it either from te std 4agze ignitor
or run it from an aux output from the haltech


what ignitor are you running

some aftermarket ignitors have a tacho output too

but just like the std ignitor u might need a signal booster

[cri_ag]

im running the haltech twin channel ignitor and two haltech dual output coils. yea might have a go wiring it up to the haltech tach output with that booster circuit described by hen above. how much are we talking for one of these pre made tacho bosters and are they any better than the circuits hen described above?

[Soarer_D00D]

Craig, PM me, i'll give you my mates number who wired up my Wolf, get him to check it out... He's a freak.