UPDATE
So it's definitely been awhile since I've updated this. The S12 has been sitting for awhile, and I recently dived back into it again. So, I'll update where I'm at with everything.
- Did not replace head gasket because it wasn't necessary. I had 165psi on all cylinders.
- Replaced all injector clips and insulators.
- Replaced temp. sensor and clip for it.
- Replaced all vacuum lines with new lines.
- Has new timing belt and water pump. I have to dial in ignition timing still.
I need to replace my intake pipe and couplers. Upon closer inspection I realized that the clamps were doing absolutely nothing because the 80's rubber couplings are hard as rock, and severely cracked allowing unmetered air in. I feel like this may be a big part in why it's running very poorly still.
So yeah, the car will actually start up and "run", kind of. It fires up every time now. It goes back and forth on needing help idling, and other times it idles perfectly by itself. Again, I need to dial in ignition timing, and replace intake pipe and couplers. Also, gonna properly check out the IAC and air regulator again. Can't remember if I cleaned those out or not.