Two things point to the brittle vacuum lines by the battery area. I suspect the high pressure spray hit a vacuum line (all C4's will have brittle crumbing lines by now) so you have created a vacuum leak. Follow all from the distribution links aroundthe battery area, and along the IM. Your AC will not operate the vent diverters and you will not idle due to the vacuum leak.
Let us know what you find....all the lines need to be replaced as they all crumble when that age.
