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I know I'll catch flak for trying to get one of these to work since all you rich people have gone to the native support MS's but I really enjoy using my self-soldered DIYPNP since I'm trying to do every part of this build first hand that I can.
That being said, I can connect to the box with the VVTuner software but get 0 RPM signal.
- DIYPNP running off CAS so only VVTuner is getting crank/cam signals. Car runs great without VVT but want all the twerks.
- Already checked crank wheel
- Confirmed 12V, ground, and signal from sensors (ckp and cps are powered and signal forwarded through now unused egr plugs, grounded directly to engine)
- I know VVTuner has control of OCV since you can hear the valve click if you plug it in with car off, and with car on it runs like on 2 cylinders at idle and dies
- VVTuner reads MAP as accurately as Tuner Studio
Re-reading DIY's instructions I thought maybe I needed to do this:
"If the VVTuner CCM and EMS share the same ground or a direct ground to the EMS is undesirable, pins 9 and 10 can be connected together either by way of a short piece of wire or a solder bridge between the two pins."
Below picture shows ugly solder blob connecting 9 and 10.
This led to blowing the fuse the VVTuner is running off of. It's powered via the power antenna plug in the trunk which is on a 15A fuse with the stereo. Before the solder it didn't blow the fuse.
So, what am I doing wrong besides refusing to spend $1000 on an MS that will make this easy mode? Could my sensors be bad? Is there a way to test? Thanks for any help!
-Billy
Last edited by silverstorm; 02-24-2019 at 12:36 AM.
Have you checked the sensor air gap for the crank sensor? I have been using a VVTuner in both my racecar and street Miata for a few years now as I started with a DIYPNP and it was cheaper to just add the VVTuner.
I run the sensor wiring through the factory CAS wiring on my racecar ('90) and inside the DIYPNP, I go from the sensor outputs on the break out board to the expansion connector along with 12+ and ground to the VVTuner. I then run the VVTuner as a pass-thru back to the DIYPNP through the same plug (Different pins of course) and to the DIYPNP mainboard to the sensor inputs.
I'll double check the crank gap. I hope it's good as is because the bolt hole that holds the sensor felt like it started stripping out the last time I tightened it. Thank you for the recommendation though.
gooflophaze, that would definitely explain blowing a fuse. I had confirmed with a multimeter that I was soldering the right pins but it makes too much sense not to confirm again.
On the DB15 face there should be the pin numbers embossed by the pins - might have to catch the light just right to see them. It's always annoying to try and infer them from documentation because it'll be reversed male to female / documented from the front and back.