310HPS2k

Alright guys I have swapped a H22a4 for my Hatch and i have a p28 ecu.

Everything is wired up and its giving me problems.
A shop checked it out and came to the conclusion it is the wiring harness.
The alternator is not getting the "right" signal to to do what it suppose to do. only 12.x volts to the battery.
Also the idle is giving me a problem too, something with the "signal" keeps stalling when I let off the gas (letting it off slowly and smoothly, doesnt stall).

The shop has checked out the harness and its hacked up. Car runs fine, motor was built and healthy.

Any opinions? Advice?

Is there anyone here who are experts at honda wiring harness? I need someone to make me one for this car/swap.

Thanks