Hi Nick, Looking at the weather today and the symptoms you are having it sounds like the MAF is or has gotten wet. Do you have a ‘cone’ air filter? If so the air flow sensor wire could be getting wet. It always gave those symptoms on the 300zx running an open filter in the wet. Also check the MAF electrical connectors too. Even if you have a stock intake it may be worth opening it up and checking the filter + MAF, at least it rules it out if you don’t find anything. DON’T go touching the wire sensor though as its fragile !!!