Broken wires!

Bad connections can be impossible to troubleshoot.

Amanda's car (2000 Protege 1.8L) has been having drivability issues, and a P0300 error code (random misfire). Gas mileage was awful, it was seriously down on power half the time, idle was low and shaky, the exhaust smelled like gas.

After a lot of driving around with the computer hooked up and trying a number of things, my dad and I deduced that the coil packs were overheating. They're mounted almost directly above the exhaust manifold. So we ordered the part (~$100 from RockAuto). When the new coil arrived, I went outside and replaced it only to find the problem was still there. When I was putting the original coils back on, I noticed the problem above. One of the three wires for one coil pack had broken off at the connector.

Soldering when you have no room to strip insulation is tough. It's additionally difficult when you do this in a parking lot on a chilly March night with only a flashlight to illuminate your work. But I managed a good enough connection, and the problem is gone. The solder will hold until I can hack a new connector and wires from a junkyard car.

Problem is, Proteges aren't particularly common. And unlike the very common 1.8L BP engine, this 1.8L FP was only in the Protege ES in 1999 and 2000. The later 2.0L FS engine is related, but didn't use these coils. Finding a plug and pigtail might take a while.