I've been working on one of my kid's 97 Grand Cherokee for months. It runs good one day, won't run at all the next. Runs like crap the next. No rhyme or reason as to when it runs good, when it runs bad and when it just dies completely. We've replaced just about everything on it sensor-wise. Every time, it seems to fix the problem, only to have it come back in a day or two. We went to Pull-A-Part a few weeks ago to pick up a couple of engine computers and try them, since that's what ended up finally fixing dozens of others with the same symptoms that I've read about. They had about a dozen cars on the lot with a computer that would interchange. Two of them had been put on the lot in the last two days. When we got there, ALL of them were missing the computers. Seems to be a WAY too common issue with Jeeps of that era.
