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1999 to 2001 VVT
I had completed the 2001 engine install in my 1999 Miata LS and it was running well. The VVT was not connected but the engine ran just fine without it. Since I was experimenting anyway I decided to try and take advantage of the extra power the VVT offers. So, I did a little research and found that I could purchase a VVTuner from: http://www.diyautotune.com/ to manage the VVT. I purchased the VVTuner-C and the VVT-Piggy harness.
The instructions that came with the unit left me with several questions. I called and talked to DIY Auto Tune’s tech support. They confirmed they did not sell the connector that attaches to the VVT Oil Control Valve on top of the valve cover and they could not help me with pictures of how to make the connections under the dash.
I consulted the OEM wiring diagram. I had to figure out the wires locations, colors and where to tap each wire at the PCM for signal, ground and B+ using OEM wiring diagrams. It sure would help if the VVTuner instructions included pictures or drawings of each connection under the dash so I could have found the locations for connections quicker.
I made my own wiring diagram and added the wire colors so I could easily locate the wires under the dash and pick a tap location. I included the connection paths and wire colors below.
I went to the local AutoZone and purchased some materials to make the connections to the VVTuner. This is what I bought.
I used a piggyback fuse holder to tap B+. I just had to confirm the tap was made to a fuse that is switched on with the ignition. I chose the Turn 10A fuse location. The piggy back device allows the existing 10A fuse to plug into the slot closest to the fuse block and I used a 5A fuse for the VVTuner.
There are three PCM connectors, one on top, one in the middle and one on bottom. The VVTuner operates in parallel with the PCM . So I had to locate the Cam Position Sensor signal Gray/Blue wire and the Crank Position Sensor signal Gray/Red wire on the middle PCM connector.
I stripped some insulation off the two wires to prepare for them for soldering a lead to the VVTuner connector. It is hard to see below, but both wires are stripped.
The Red wire was soldered to the Gray/Red PCM connector wire and the Blue wire was connected to the Gray/Blue PCM connector wire.
The ground had to be connected by running a wire out to the engine and connecting at the intake ground. I ran a black wire for the ground.
For the VVT control wires I ran a Red and Blue wire from the driver's side under the dash to the Oil Control Valve (OCV) on the valve cover. I made my own version of a three conductor cable by taping the Red, Blue and Black wires together and pulled the cable from under the driver's side dash out to the front of the engine. I also pulled the vacuum line at the same time.
I found a grommet on the firewall in front of the passenger seat. I pulled the grommet out and pushed a coat hanger wire in the hole until I could find it under the dash.
Then I fished a string under the dash and over the hump with a coat hanger wire to get to the driver's side.
This is the vacuum tube being pulled with the coat hanger wire.
The string was used to pull the wires and the vacuum line.
I used a small leather punch to make a round hole in the rubber grommet. Both wires and the vacuum line fit through the hole.
I used some Blue split loom to cover the wires in the engine compartment.
I found a Ballenger Motorsports connector with pigtail part# CONN-85734 http://www.bmotorsports.com/shop/advanced_search_result.php?x=0&y=0&search_in_description=1&keywords=CONN-85734 that I thought should fit the OCV socket. I ordered one to see if it would work and it fit fine. The ground wire was connected to the ground connection just below this connector on the intake manifold with a crimp on loop connector.
I also had to tap a vacuum line to feed the controller and run it into the passenger compartment. I used a Tee connector and connected to the vacuum connection on top and in front of the intake manifold.
The VVTuner needed a solid mounting location, so I chose the steering column cover under the center of the driver's side dash. It has a metal structure that I drilled and tapped. Then using short screws mounted the VVTuner.
All the wires had to be connected from the VVTuner harness to the wires I had run to the car. I labeled everything for later reference if needed.
I connected the wires as follows:
The Gray/Red wire at the PCM was connected to a Red wire I added as mentioned above. Then the Cam Position Sensor signal Red wire was then connected to the VVTuner connector pin #4 white wire.
The Cam Position Sensor signal Gray/Blue wire at the PCM was connected to a Blue wire I added as mentioned above. Then the Blue wire was connected to the VVTuner connector pin #3 Green wire.
The Blue and Red wires from the Oil Control Valve (OCV) on the front of the engine was connected to the VVTuner connector pins #8 and #15 Purple wires. The instructions did not indicate polarity so it was apparently unimportant. Tech support confirmed that.
The Black ground wire was connected to the VVTuner connector pin #9 Brown/Black wire and also to connector pin #14 black wire. Tech support confirmed that pin 9 should be grounded also if not using the additional EMS connections.
The Red wire connected to B+ at the fuse was connected to the VVTuner connector pin #5 Orange wire, pin #6 Orange wire and pin #7 Red wire.
The vacuum line was connected to the other end of the VVTuner.
Here is the final set up. Notice the Red LED is lit when the key is on.
I have yet to change the programming, but due to my limited knowledge of tuning, probably will just use the factory settings that came with the VVTuner.