Tach Wiring -Megasquirt/Wasted Spark

[JCarp90]

Hi guys -

I have a question for you all. My car does not have a stock cluster so I'm using an Autometer Tach. The tach used to pull signal from the ground side of the ignition coil, but I recently converted to wasted spark, so no more coil. How would you go about wiring the tach?

Thanks

[jperris]

Your ECU outputs an engine speed signal on pin 6. If the stock cluster wiring is intact, it should go to pin 7 (black wire) of the 26-pin blue instrument cluster connector.

edit: just noticed your post title suggests Megasquirt. Doesn't the MS control unit have a tach output?

2nd edit: ....and now I see a mod has moved your thread from gen tech to the alt tuning forum. i'm outta here.

[JCarp90]

Your ECU outputs an engine speed signal on pin 6. If the stock cluster wiring is intact, it should go to pin 7 (black wire) of the 26-pin blue instrument cluster connector.

edit: just noticed your post title suggests Megasquirt. Doesn't the MS control unit have a tach output?

2nd edit: ....and now I see a mod has moved your thread from gen tech to the alt tuning forum. i'm outta here.

That was what I planned on doing, but I don't have any of the original harness still in the car. Everything has been re-wired. I was advised to splice into the RPM signal into the DME, but that didn't register anything at all.

I'm not sure why my thread was moved, it's not really related to tuning/MS.

[whodwho]

It should of worked from the tach out on the ECU but you can still drive it from the coils like this

[JCarp90]

It should of worked from the tach out on the ECU but you can still drive it from the coils like this

Good deal. I'll give this a shot.

As always, Whodowho saves the day.

[nando]

MS2 and 3 have a tachout pin. that's a lot simpler than a bunch of extra hardware. all you need to do is jumper the tachout header on the board to one of the spare pins on the DB37, turn it on in tunerstudio, and plug it into your tach.

you can't hook the crank sensor to the tach, which is what I think you were saying in your other post.

[Jaxx_]

MS2 and 3 have a tachout pin. that's a lot simpler than a bunch of extra hardware. all you need to do is jumper the tachout header on the board to one of the spare pins on the DB37, turn it on in tunerstudio, and plug it into your tach.

you can't hook the crank sensor to the tach, which is what I think you were saying in your other post.

this. I run a megasquirt tachout to a crappy autometer tach and it works just fine. you might have to do a few small mods on your megasquirt board. The information is on the msextra site concerning the different tachout setups:

http://msextra.com/doc/ms2extra/MS2-Extra_Hardware.htm