badmanners
Member
Hi guys. My friend bought a 2005 Mazda 6 2.3/5spd with a blown engine. Rods were knocking and it was misfiring.
I replaced the engine for him with a used mazda 3 2.3 engine that had 140,000km on it.
I also put him a new coil pack. Wires and spark plugs for good measure.
After the job was done we went for a test drive. There was a slight hesitation from idle to 3000rpm and then the car felt normal.
No check engine. No codes in memory. We continued test driving the car when finally the check engine came on and started flashing.
I pulled the codes. P0300 Random cylinder misfire. With the car running I removed each plug wire from the spark plug. On cylinders 1 and 4 there was no change in idle. On cylinders 2 and 3 the car almost stalled.
I turned off the car anf probed the 3 wires going to the coil pack. Center one is 12volts with key on. Left one and right one pulse ground when cranking with the coil pack disconnected from the harness.
When I plugged in the coil pack and redid the test the left wire is pulsing power. Center wire is power and the right wire is pulsing ground as it should.
Defiently sounds like a burnt ignition coil driver. Is this something common?
If I do find a replacement pcm. Do I have to replace the key and transmitter to match?
I replaced the engine for him with a used mazda 3 2.3 engine that had 140,000km on it.
I also put him a new coil pack. Wires and spark plugs for good measure.
After the job was done we went for a test drive. There was a slight hesitation from idle to 3000rpm and then the car felt normal.
No check engine. No codes in memory. We continued test driving the car when finally the check engine came on and started flashing.
I pulled the codes. P0300 Random cylinder misfire. With the car running I removed each plug wire from the spark plug. On cylinders 1 and 4 there was no change in idle. On cylinders 2 and 3 the car almost stalled.
I turned off the car anf probed the 3 wires going to the coil pack. Center one is 12volts with key on. Left one and right one pulse ground when cranking with the coil pack disconnected from the harness.
When I plugged in the coil pack and redid the test the left wire is pulsing power. Center wire is power and the right wire is pulsing ground as it should.
Defiently sounds like a burnt ignition coil driver. Is this something common?
If I do find a replacement pcm. Do I have to replace the key and transmitter to match?
