2.9L EFI Electronic Advance issue
Have a 1986 2.9L fuel injected that idles alright but when you put it in first and actually take her through the gears she misses throughout the entire range and all RPMs (so bad it jerks the truck violently). I have changed plugs, checked distributor, plug wires, and timing, changed fuel filter and checked fuel pressure. Big clue came when i removed the chip that disables the electronic advance (like you're supposed to do when you time the engine) and she drove smooth as can be with no missing (but lacked obvious power due to E-Advance being disabled). What would this likely be...the PCM (EEC-IV), ICM (TFI-IV), or some random sensor.