The PCM sends ground pulses to the injectors to trigger the injectors on / off. With ignition key on, in either start or run the injectors will have 12 volts.
dave w
Can someone tell me what a normal injector base pulse width is for idle on a similar engine? From my logs it appears that it will idle with the bpw above 2 but dies from the lean condition when it is below 2. I am trying to determine if the lean condition is being commanded by the pcm or if it is due to a mechanical or electrical fault.
I would try swapping the ignition module from the good runner into it or the whole dizzy .it may have good spark and an rpm trace on the ecu but not enough current to make the ecu trigger the injectors properly.i had a test bench that wouldn't fire the injectors but would show rpm in datalogs fine just my rpm trigger circuit wasn't supplying enough grunt to get the ecu to actually fire the injectors.
I fixed it today, and I'm feeling a bit sheepish.Attachment 12234
It was a fuse.
I have few excuses, except that I never questioned a fuse because I thought it wouldn't start or fire the injectors at all if there was a fuse issue.
I understand that the PCM connects the ground for the injectors to fire them. What is apparent now is that the start circuit and Acceleration Enrichment circuit are apparently parallel to the main injector circuit. Meaning that it can provide fuel for AE and starting without the main injector circuit being functional.