98 2.2l wont start

Hello, I am trying to fix my mom's s10 she just bought. Its a 98, 2.2l w/auto trans and 195k miles. A couple days ago she was driving it to my shop so I could replace the leaking water pump... She called me about 2 miles away and said she was broke down. I got there and found the #4 spark plug had blown out of the head (still in the wire) She herd a loud popping noise pulled over and shut the truck off. We towed it back to my shop, I tapped the spark plug hole and was lucky enough to thread the plug back in. Now it wont start! It will turn over fine but no start. I replaced the plugs and wires (looked a little worn out). Still no start. Checked for spark and it did spark at the plugs although the spark seemed a little weak. tried some starting fluid, still no start, checked the fuel pressure and bleed off, all good. Tried putting in new coils, still no start. Checked for power at the ignition module and it was good. checked compression, all at 75psi, I think my gauge maybe be off because they were all low but still the same. I have no idea what to do next. Any help would be great! I'm really banging my head against the wall here. P.S. sorry for the long story Thanks!!