I had my V40 for 2 weeks before I began getting rumbling and a cylinder 2 misfire code, so I replaced the cylinder 2 spark plug. Now, the engine turns over but does not start. I have replaced the spark plug wires; same result. Is there something I'm missing? What's next?

 

what year?

 

2004.

I tried again and now it will not even turn over, just crank:

 

usually turning over and cranking mean the same. If the starter motor is spinning the engine but it doesn't start, you either have a fuel pressure issue or a spark issue. My bet is you have an issue with the fuel pressure regulator which can cause start issues on the 1.9T. Quick test is to find the pressure regulator (bolts onto the driver's side of the fuel rail - has a fuel line running into it). give it test start then pop off the vacuum line on the bottom. If fuel drips out of the vaccuum port, you have a torn diaphram that's leaking fuel pressure which makes it hard to start. Next would be to measure the fuel pressure if that doesn't show you anything to test if you have a fuel pump relay or fuel pump issue. You can try jumpering the relay to see if you can turn on the pump to build up pressure for a start up. Next possibility is the spark. Not uncommon for these cars to develop cracks on the connectors from the wiring harness into the coil packs. You may have a bad coil pack, an issue with the jumper wire or the wire harness that runs from the firewall. Finally, you may have washed off some of the oil off the piston rings with all the failed attempt which lowers compression. A quick compression test would let you know.