VVT Engine Swap Ignition

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1999 to 2001 VVT

Engine Swap


The 2001 engine has coil over plug ignition setup with two coils each feeding two spark plugs. The 1999 and 2000 Miata coil pack has two coils mounted on a bracket at the rear of the head that each feed two spark plugs. The same two spark plugs are served by the same coil on both the 1999/2000 and the 2001 Miata. Coil #1 feeds spark plugs 1 and 4 and coil #2 feeds spark plugs 2 and 3. Therefore, I found that the use of the 2001 COP ignition was possible without swapping the PCM (ECU). I included some links below where I found some of the data.

Original 1999 engine and ignition.

Vendor Links

The Parts Group

2001 engine and COP ignition.

None of the information I found included a final wiring diagram with the 2001 coil pin-out information. So, I also had to come up with my own wiring plan. First I consulted the OEM wiring diagram. The wiring diagram shows how things are connected and wire colors, but not the coil pin-out information. I finally found that the top spade on the 2001 coil is the Trigger, the middle spade is the Ground and the bottom spade is B+.

This is how I connected the 2001 COP ignition to my 1999 Miata’s wiring harness.

· Coil #1 connector with blue dot that feeds plugs 1 & 4

o Brown/Yellow Trigger wire to the top spade on the 2001 coil

o Black ground wire to the middle spade on the 2001 coil

o Black/White B+ wire to the bottom spade on the 2001 coil

· Coil #2 connector that feeds plugs 2 & 3

o Brown Trigger wire to the top spade on the 2001 coil

o Black Ground wire to the middle spade on the 2001 coil

o Black/White B+ wire to the bottom spade on the 2001 coil

In my engine swap research I could not find how to make the 2001 ignition system connections to the 1999 wiring harness. Some threads mentioned using an old 2001 harness for the connectors which is an excellent idea. But, I could not find a 2001 harness at the time. Another thread referred me to Ballenger Motorsports for connectors, but I was unsure which connector to order. So, I searched junkyards for connectors.

I found a 2002 Nissan Altima six cylinder that had the same type coil connectors in a junkyard. Notice the red wire on the Nissan coil connector. It matched the B+ 2001 coil connector.

However, after making a harness with these connectors, I got a random misfire code P0300. I found water was getting into the connector. Turns out this was not causing a problem yet. The fuel pump was not keeping the pressure up causing the misfire code.

So, I pulled the makeshift harness and rewired the connections with Ballenger Motorsports part number CONN-85775 connectors. They fit my 2001 coils perfectly. They also seemed to clip on properly so the zip-tie was no longer needed. Hopefully, they will make a water tight seal.

I soldered them in just below the 1999 coil pack connectors and left the 1999 connectors intact. I am test driving the car to see if the code reappears.

I went with the 1999 intake, the 2001 COP ignition, and used the 1999 exhaust manifold so I could use the 2001 exhaust manifold on my supercharger install.

Here are some of the threads I used for researching how to make the engine swap. They helped me decide which intake, ignition, exhaust, etc. to use.

For basic info.


Closest thread I found to pin-out of 2001 coils.


1999 and 2001 Intake pictures with differences made clear.


1999 intake cleaning.