Hi guys new here, so here is my problem just bought an amazing Montero 2000 I have worked on it a bit but now I am having this weird problem where it starts and runs and everything but even if you put the pedal like full down, trynna get it to go the fastest it can, it doesn’t, it goes like 20 miles per hour at maximum and doesn’t rev limit, so I don’t understand because when the car is idle I can push it all the way an it will rev perfectly, have been having this since a week or so, I don’t really want to take it to a mechanic so trying to get help here.

 

Too many possibilities to just starting to list. You need to plug in a live data stream capable code reader/computer and see what is happening when you drive.
First suspect is air/fuel disballance