If you're smelling fuel, then your FPR is probably bad. That's cheap and easy, so I'd do that first.

I'd also check the AMM (swap in a known good one). I've had a bad AMM cause an intermittent bad idle--some days it was ok, other days not. Also, my bad AMMs almost always caused symptoms only at idle, the cars ran fine on the road. Though with a bad AMM, I'd expect it to run worse after you unhook the battery while the ECU learns to re-adjust.