Check for a vacuum leak somewhere.

 

No vacuum leaks that I know of. I replaced a few lines already, thinking that was the problem. I also checked with propane by the lines, no change in idle. Is there a way to check the ECT? Correct me if I'm wrong, but there is one sensor for the gauge and one for the pcm... My gauge reads properly, but maybe the one for the pcm is done?

Thanks for all suggestions, hopefully I can fix this soon!

 

I believe that a '97 has two sensors. The one for the gauge will be in the head while the one for the PCM will be in the lower intake manifold at the thermostat. I posted resistance values based on temperature somewhere around here...