Long story short,

I have a buddy with a built B16 turbo Del Sol and every time he is driving and comes to a stop or an idle, and the radiator fan comes on, or he rolls his windows down or turns on the headlights, the engine stalls. Idle is set at 900-1000rpm.

He has changed out nearly the entire charging system, from the battery, fuse box, alternator, to a different engine wire harness, still the same thing.

We have changed out the thermostat, temp sensor, IACV, TPS.

We have tried a stock P28 ECU, different from his Hondata S100, still the same thing. We have had two different tunes by both Church and Bisi. He has replaced all of his engine/chassis grounds. He has sanded down all the points of contacts for the grounds to bare metal, nothing has changed nor helped the situation.

Only thing we haven't tried is a different throttle body and different distributor.

Anyone ever seen this or have first hand experience with something like this?

TIA