Tachometer not working
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Todd Cagle
- MS/Extra Newbie
- Posts: 9
- Joined: Thu Jun 29, 2017 10:44 pm
Tachometer not working
So I'm running megasquirt3 with a 3x board and I have my tach running from the jp3 jumper to the tacho output. On tuner studio I have the corresponding output "tacho" set as the tach output and it won't work at all. I decided to try a different output so I tried spark H and without even connecting the spark H output wire the tach started working perfectly fine. I turned the car off and on and it seemed to work great until I got in my car an hour later and it wasn't working. I tried changing the outputs but still nothing. Everything in the car works so I'm scared it's not a bad ground but I do plan on strengthening the grounds I have with some thicker wire and better grounding points. Please help if you have any ideas! Thanks in advanced! P.S. it's a 1998 vw golf with a 3.2l vr6 running the stock vr6 Gti cluster.
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billr
- Super MS/Extra'er
- Posts: 6828
- Joined: Sun May 15, 2011 11:41 am
- Location: Walnut Creek, Calif. USA
Re: Tachometer not working
Another new thread getting no love? I know little about driving tachs (mine uses a speedo-type cable), but will offer some basic suggestions.
I would go back to the "tacho" output, figure out what is wrong rather than just trying the spark outputs. By the way, when trying spark H did you connect a pull-up to it; similar to what JP3 provides for the tacho?
Regardless of what output you use, try reading voltages with a meter. Try both AC and DC ranges. AC should give better results (react to a signal), but if the output is "stuck" at either a DC high or low, that is a good clue.
Try connecting the output you are trying to use to the cam input and getting a composite or high-speed log; let's try to get a peek at that wave. You may not be able to do this if your triggering mode requires the cam input, but I can't tell about that right now because there is no MSQ to look at...
I would go back to the "tacho" output, figure out what is wrong rather than just trying the spark outputs. By the way, when trying spark H did you connect a pull-up to it; similar to what JP3 provides for the tacho?
Regardless of what output you use, try reading voltages with a meter. Try both AC and DC ranges. AC should give better results (react to a signal), but if the output is "stuck" at either a DC high or low, that is a good clue.
Try connecting the output you are trying to use to the cam input and getting a composite or high-speed log; let's try to get a peek at that wave. You may not be able to do this if your triggering mode requires the cam input, but I can't tell about that right now because there is no MSQ to look at...