I recently have been trying to switch away from a Microsquirt ECU on a 383 TBI, putting the old 7427 PCM back in and acquired all the chip burning hardware. With the MS (Microsquirt), I had it running and driving pretty good, but putting the original PCM back in (and changing the Displacement per cylinder to a 383 in the Binary file) it ran terrible and would not drive in gear. The O2 was reading rich then lean back and forth, nothing crazy, but adding more throttle after 5% made no more power and sounded horrifically lean. I popped the lid off the air cleaner and the passenger side injector was not spraying at all, Driver side was fine.

The thing is that if I put the old MS setup back on, both spray as normal and drives fine. I don't know if its a hardware problem or tuning problem but it is driving me up a wall. Does anyone know what the heck is going on? I've compared my modified bin against the original BJLF bin for a 1994 Blazer L05 4l60e and I didn't change anything other than Displacement constant, VE, and EGR. I'm probably going to open up the PCM case and have a look but wasn't sure if this was a known issue or not.