Hey there guys, I have a 89 cherokee 4.0 that I've been having some problems with, when I start it, sometimes it revs up to about 3k rpm. And when I put it in drive or reverse, it stays pretty high, I was told this could be a vacuum harness problem, so I'm just looking for suggestions and help with this, thank you everyone!

 

If you search up posts under my username with the string "vacuum leak," you should be able to find how to test it.

That same search should give with the part numbers for replacement vacuum tubing through NAPA (Echlin brand,) three parts for about $50 should do it. They usually have a set on the shelf.

 

It's more than likely a problem with the TPS or sensor grounds.

Click on the link in my signature and do posts 1,3,4, and 5 before getting off on any tangents replacing parts.