Engine wont start when hot!!! help!

[v8vinny]

I looked all over the car and it had no engine ground. But it also has the battery mounted in the trunk so the negative cable cant be grounded to the block, but it is grounded to the rear frame section. We added a motor to firewall and motor to k-member ground, and you guessed it still same problem. I havent been near the car in a few days I've been sick, but my next step is to pull a plug when its hot and see how they look. I havent had time to sneak my scan tool out of work to go check it for him either, and i cant go by the check engine light being on because i dont think it works, becasue the o2 sensors are not attached and there is no light.