Hi, guys. I hope everyone is doing good.
I have an old Honda City 2001 EXI-S automatic, engine swapped with D16.
The problem I am facing is that when on AC the car's RPM drops considerably instead of going/adjusting up, and it feels like AC/Compressor is taking too much load, specially at idle.
Important to mention here that AC/Fan isn't direct and electrical connections are routed through ECU. Connecting with any OBD scanner it clearly shows ECU detecting AC on/off & fan on/off. Also checked IACV readings with AC on/off and it seems ECU is trying to compensate for the increasing compressor/AC load as with AC off IACV had a reading of 20-22%, when AC is switched on ECU increases it to 40-42%. But even after that RPM doesn't go up. Also sometimes I have noticed they go 50-100 RPMs just for a split of a second as soon as AC is switched on, and then drops.
I am leaving Idle RPMs reading below:
Idle, cold start: 1000-1100 RPM
Idle, once engine is at operating temperature: 850-900 RPM
Idle, AC is on: 600-650 RPM
On AC sometimes the RPM goes so low that car starts RPM hunting, jumping between 500-700 RPMs.
Can you guys please help me with what's the issue here and what other things that I should be checking?
Thanks!