Keep the TB spacer, get a CAI and one of these. I have extras if you need one. 
Throttle Body Spacer
- Thread starter Halbarad
- Start date
The info should be in these threads:
https://wranglertjforum.com/threads/throttle-body-leak-bushing-or-seal-replacement-options.68008/
https://wranglertjforum.com/threads/1999-tj-tps-throttle-body-question.31702/
I used the YouTube video mentioned in there as a reference. I don’t recall the o-ring size but it’s either in the metric or SAE kit from Harbor freight, and it becomes intuitive regarding which seal is correct.
Edit: I experimented and did two o-rings on one side of each bearing vs one o-ring on each side of the bearing. It sealed better with them stacked on the same side.
Last edited:
This is all true although for my Jeep to maintain or Increase in speed easier on grade indicates that there is an increase in torque. Torque gets you moving and horse power keeps you moving.
Yes it also moves the I rings to a new spot on the shaft,I already bought the rings from ace,just haven’t had time to install,did you just use regular grease,thanks
Yea I remembered that only after fetching up the older posts on it. I used silicone grease since it wouldn’t break down the petroleum based o-rings I used.
On a 98-04 JTEC/JTEC+ PCM, the throttle position shows up in only a few places in the PCM configuration. Most functions are driven by MAP, but the TPS does drive the switch to wide open throttle, power enrichment and a few other things.
I also have a BBK 62mm, but I've also done mods that really have an effect on power. Roller rockers, tuning with a wideband O2, headers, cat back exhaust and intake. I plan to go much farther on an NA setup where eventually the throttle body will make a difference, but I'm not there currently. As is, my assessment is that the BBK is not causing any issues aside from a bit of whistling, but as was shown by Jezza's bolt on dyno tests, it's giving no torque or hp gained until you start to get well above the horsepower the 4.0L was designed for.
I also agree that it increases the amount of air passing by the valve at part throttle, at a given pedal position.
I also have a BBK 62mm, but I've also done mods that really have an effect on power. Roller rockers, tuning with a wideband O2, headers, cat back exhaust and intake. I plan to go much farther on an NA setup where eventually the throttle body will make a difference, but I'm not there currently. As is, my assessment is that the BBK is not causing any issues aside from a bit of whistling, but as was shown by Jezza's bolt on dyno tests, it's giving no torque or hp gained until you start to get well above the horsepower the 4.0L was designed for.
I also agree that it increases the amount of air passing by the valve at part throttle, at a given pedal position.