05-25-2017, 08:37 AM
Agreed ! Found a local electronics guy to replace all caps and transistors (well, he'll test the transistors first, as physically they look good), including C48 which is a tiny surface mount fellow. So no more hot wiring. Will be an interesting moment of truth when I reconnect fixed ECU and turn key !
BUT, I still don't understand how hot wiring through a fuse to the injector can damage it? If injector is 1 ohm and I'm feeding 12V through 5A fuse, then I can never reach the peak current of 12A that would occur if I maintained a constant 12 V across the injector, as the fuse would blow first, and yet it doesn't? Seeing as though ECU grounds the negative side of injector to fire it, how can injector tell if the 12V came from ECU or other source? What am I missing? [my electronics knowledge fairly primitive !]. My thought was ECU provides positive so that it can decide not to if it detects some other issue in the engine (so I risk some other issues, but not injector damage, but I don't know what)
BUT, I still don't understand how hot wiring through a fuse to the injector can damage it? If injector is 1 ohm and I'm feeding 12V through 5A fuse, then I can never reach the peak current of 12A that would occur if I maintained a constant 12 V across the injector, as the fuse would blow first, and yet it doesn't? Seeing as though ECU grounds the negative side of injector to fire it, how can injector tell if the 12V came from ECU or other source? What am I missing? [my electronics knowledge fairly primitive !]. My thought was ECU provides positive so that it can decide not to if it detects some other issue in the engine (so I risk some other issues, but not injector damage, but I don't know what)