matth0le
+1y
Well the wiring is not all that difficult for me. I was an aircraft electrician though. If you are comfortable with rewiring something and have some clue of what you are doing then I would consider this fairly easy. I kept as much of the Kia harness intact. The entire engine harness stayed on the engine. There is another harness that has a fuse block/starter relay and battery connnection that plugs right into the engine harness. That left one cable with open ends and no connector. From there I just made a few connections to the Mazda harness behind the pass headlight. I used the Kia online service manual (a total lifesaver) and a Mazda Haynes manual for electrical diagrams.
It took me a bit of time to figure what wires were needed and what was not but was easy for me. For me I would give it a difficulty of 6 out of 10. If someone were walked through what to connect it would probably be a 5 out of 10 difficulty.
The engine and transmission bolt together as if they were made to go together. The Mazda and Kia engine mounts are different and must be swapped but everything bolts right up on the engine and tranny. The Kia oil pan is too deep and will need your old mazda oil pan and pickup tube. It was an easy bolt for bolt swap-over.
One other thing that worried me was the Kia crank angle sensor that mounts on the transmission. The Mazda of course does not have a hole there to mount it to so I made a jig to line it up and used a hole saw to drill through and mount the sensor. It is a magnetic pickup type sensor that reads breaks in a magnetic field (notches cut into the Kia flywheel).
Everything else was minor (in-tank fuel pump or tank with fuel pump installed, throttle cable mount, mount for emissions evap canistor, power steering lines, radiator hoses, A/C lines, fuel lines).
As far as emissions go I would not sweat it. I live in Vegas and emissions is nearly as strict as CA. I kept all emissions parts (o2 sensors, both cats, fuel vapor cannistor, ECU, all valves, etc) in the system so it should meet 2002 standards much less 1988 standards.
There might be a few other things I forgot. So far the engine starts up great, idles great, drives fine but I have not put it through abuse yet. I will go for an emissions test this week and will keep posted on how it performs.
Matt