Originally posted by Slo2g
Try running the ground to the chassis or an existing ground. Where do you have your power for the MSnS tied in? Are you leaving the factory ecu in the car or are you removing it?

I did that. Actually today I put it on a scope and with the ms not attached I had a very nice wave form, only when the factory ecu was connected also, I'm not really sure why that mattered. I did not however have a tach signal on my factory dash? But when I put the ms unit back into the equation I get a wave but it only goes to 2v, which makes me think my problem lies in the ms. Me and my dad looked over the directions and it looks like we skipped over the part where you replace r12, remove a capacitor and jump 5v to where the capacitor was. I know that the factory ecu uses a comparitive circuit to read the signal, is this what ms needs to do, more specifically is that circuit we missed the comparative curcuit? Could that be my problem? Either way that's on the todo list for tomorrow. Also as a side note, beware when buying a diyautotune harness, 5 out of my 6 grounds were in the wrong place on the db37 harness. But that didn't fix my problem:(

Thanks sorry it's long.