1998 Chevy Metro 4 cyl Front Wheel Drive Automatic
Fuel injectors 1 and 3 are not getting a trigger pulse from the ECU. 2 and 4 trigger fine. Got a used " good" ECU and it had the EXACT same symptom. Can't be the ECU right!
1 and 3 can be triggered manually with a back probing jumper to ground from the respective pins in the ECU, which verifies the wire and injectors work fine.
What else could cause this symptom other than an ECU with 2 bad injector drivers? Having a hard time believing I have 2 bad ECUs!