This is a weird one. The Civic has been running a bit lean in the past couple weeks according to a wideband I've put in it, but it was otherwise seemingly OK. I figured I'd take a look at it when I had the time. Well, looks like now I don't have much choice.

I was leaving work when the Civic wouldn't start. Engine cranked, but it was like it wasn't getting any fuel or maybe not getting any spark. (Didn't smell gas, so I'm guessing no fuel.) I kept cranking and the Check Engine light came on. Then I smelled smoke - lots of smoke. It was coming from the passenger fenderwell. I pulled back the carpet and the ECU was smoking like a bong full of transistors. I unplugged the ECU and drove home in the shop truck.

So, next step is going to be to track down a used ECU, but any thoughts on what might have killed it? Just wanted to be sure there aren't any likely culprits in the wiring harness or something else that may be waiting to kill the next one I plug in. The car is a '95 Civic EX, stock engine, no mods to the ECU or the factory wiring harness other than that I bypassed a broken clutch switch a while ago (I put the wideband in without touching any factory wires.).

 

For the record, it was a shorted out power supply capacitor inside the ECU. Swapped in a junkyard ECU on Monday and it's been running fine since.