90% of weird issues like these turn out to be a ground. Especially if it just "stopped". Grounds always do that shit. Check the ground that goes from the firewall to the engine. Make sure it's got good contact with the block. A lot of people put them on the throttle cable or on the plenum that's all aluminum. I've made the same mistake and had a similar issue. Check the main ECU ground cluster that's on the passenger side under the MFI relays as well make sure thats got good contact.