I have a 97 Civic h22a swap OBD1 running a p28 ECU tuned for the swap. I have probably driven it 4-5k myself with no issues besides a broken wire at the map sensorand my vtec stopped engaging the other day.

It had been runnning perfectly for a while did a valve adjustment a month ago.

I went to pick up another vtec solenoid today, we swap it and my car starts idling funny, surging then making a random pinging and popping noise.

1. We mess with all connectors, to make sure they are on correctly, no change.

2. We pulled spark plug wires one by one to see if one cylinder was acting up when we pulled it nothing changed. when we put 1 back, the noise stopped. But as soon as we stepped on the gas, it came back.
3. I assume its an ignition problem. we broke down in front of NAPA so new cap, rotor, plugs, wires. I think it made it worse somehow

Im leaning toward a bad ecu, but I am trying to get all possibilities, and how to narrow down my search.

 

Pulled the plugs 1/4 were oily, all were black