Tach and reluctor help. EE's, please help!

[evilmiata]

I'm having some problems getting the car started and you electrical engineers might be able to help me out. I think it has to do with the reluctor, since I can't get a steady tach single (using a Haltech E6K). I can turn the gain (sensitivity) up and down, but it still is a little erratic. The reluctor only has two wires running to it and I have a feeling that I'm picking up some interference. Do I need to run some kind of grounding strap or sheilding with the reluctor wires? Can the reluctor wires be too long? All my wiring connections are tinned, hooked together, then soldered again (I heard this was military spec). I figured some of you guys know electronics a lot better than I do.

[bszopi]

RE: Tach and reluctor help. EE

Are the wires run to the crank sensor twisted?



As you can see in the diagram, the wires from the 3x sensor must be twisted a MINIMUM of 9 times per foot. A twisted pair wire set allows for any interference in the wires to be cancelled out. That is why twisted pair wires are used so often in audio cables. Since I used to build my own patch cables, the easiest way to make a nice twisted pair wire set is to take about twice as much wire as you think you will need, clamp one end of both wires into a vice and the other ends into a drill. Stretch the wires out, but don't make them too tight. Then slowly start the drill. As the wires twist, the wire set will start to shorten, so you'll have to walk with it making sure it never gets too tight. Twist it up pretty good because you will loose some of the twisting. Once its done, set the drill down and let the wires sit for 10-15 minutes. Then, undo the wires from the drill and the vice. And wa-la, a nice twisted pair wire set. You can always check to make sure you meet the minimum twists, but you should be fine. The soldering sounds good. Similar to what we did in the Navy.

[evilmiata]

RE: Tach and reluctor help. EE

Yes, my wires are twisted well over the minimum 9 times per foot. I'm probably closer to twice that. I used to sell for a telecommunications contractor, so I know how the twists work. One thing I DIDN'T think of is shielding. Looks like there used to be stainless steel grounding wire. Maybe I'll unwrap my wires and retwist them with some uninsulated SS wire as a shield.

The guy who helped me with this project builders underwater gliders (like submarines) which are also used by the Navy. He also taught me how to solder.

[Cliff8928]

RE: Tach and reluctor help. EE

I know the stock crank sensor wires have 3 wires in the harness, even though only 2 go to the crank sensor. That third wire may be the key.



Cliff Scott
89 BerettaGT
04 AleroGX