What is the best way to adjust the fuel pressure regulator on a 2.5 TBI system?

I cant say this is even possible on your Yj but I have seen some on other vehicle's that had a screw in the vac line nipple. Which way does what I dont know. Other then that Id say they are not adjustable and a new one is in order. Parts for a TBI YJ are hard to come by unfortunately but I see RockAuto does carry the diaphram kit for $52.
 
Is it running rich from pressure or is the O2 sensor off and ECU getting the wrong signal? I have MPI so I'm not familiar with the TBI system.
 
Last edited:
redbullet said:
Make sure you tighten the manifold bolts to spec and ensure none are missing. Tightening mine up did wonders for the fuel mileage
Click to expand...
Been a while! and spotted this just browsing my old post looking for IAT help. In this instance it was a loose and very old O2 sensor. But regarding bolts, later in 2023 I had a backfire in Autumn and after crazy time spent rooting around it turned out to be 1. a missing rear bolt and 2. A PO threaded bolt which had sheared and was letting air into the engine. That turned into a job from hell until I learned how to remove the entire throttle body, vacuum hoses and all that stuff around the bolt to get access. But two new bolts later and bingo. Not only did it fix the backfire but, and it's probably just my British imagination, it seemed to have more acceleration and little bit more ooomph.... As we say in my part of the country... BOSH!
 
  • Like
Reactions: redbullet
Top Bottom