Cowcreektx

Hello all. My name is Matt, live in Texas, 4 miles from hidden falls adventure park for those of yall from Texas. I'm a diesel guy but recently bought an 88' pathfinder for my daughter after she wrecked her 01' Z71. ( yes I knew it would happen. 4 months!). I found this pathfinder in my little town and it's clean as you can find. I thought it was bad a$$! They're such a cool rig. 114k on it, zero dings or dents, perfect interior, let's go! She drove it for a month and it fell on its face. I've got the 2800 rpm issue. Took it took a shop figuring a sensor but being a diesel guy I don't want to mess with it. 3 weeks later, still in shop. I'm dragging it home and about to figure this little guy out. Any suggestions? Not one to throw in the towel so i bought one from my neighbor as well. Runs good, same year, 220k on it with no title. I dig the Lego wheels which it has and my clean one doesn't so that cool. With all my research I'm finding to clean the MAF and then look into TPS. On the right track?

Please tell me someone has the answer to this dilemma