Novak Conversions Jeep Wrangler TJ engine mounts

Throttle Body Spacer

Halbarad

Halbarad

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Original poster
Joined
Feb 27, 2025
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74
Location
Morden, MB
After looking at some papers the PO had left in my Jeep, I have suspicion that they may have installed a throttle body spacer. Which makes me wonder, would it be wise to remove it? Or is this the stock throttle body?
If it is a spacer, what might change by removing it or leaving it in? If it is detrimental in some way I want it out. Unfortunately I have no other TJ nearby to compare.
IMG_5435.jpeg
 
Halbarad said:
If it does not hurt it then I will leave it for now.
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It shouldn't have any significant effect on performance either way, but there's a decent chance that it causes a whistling sound, so if you hear one, that might be your source.
 
jjvw said:
Or just use a new gasket when you remove the spacer. Doing a smoke test for any of this seems silly if you aren't trying to find a vacuum leak.
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Baseline test. So many things ooze smoke in mine but no vacuum or idle issues. If you check while it's working then you'll know what the difference is when it's not.

-Mac
 
Halbarad said:
Well I have had issues in the past with vacuum lines so a smoke test probably would not harm me any.
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Then you are doing a smoke test for other reasons than to prepare for removing a throttle body spacer. 🤣
 
Moglocker said:
My t/b smokes bad around the the throttle shaft,but no good replacements available.
Click to expand...

Several years ago I was having problems with idle fluctuations and what appeared to be a lean idle miss...
After quite a bit of troubleshooting I discovered the throttlebody was drawing air in between the body of the throttlebody and the throttle shaft.
Researched a replacement and didn't feel confident purchasing one of those online refurbished parts so I looked into a new BBK 62 mm throttlebody.
Once I decided that BBK was the one I found a 25% off SALE on one.
I disconnected the battery ground lead while installing (ECU reset for air/fuel calibration); upon startup the ECU had to adjust idle RPMs.
Went for a drive for 45 mins and the increase in throttle response was quite noticeable.
There is a steep bridge on the way to the JAX airport that required me to downshift to 4th with the A/C on to maintain 55 mph; now I can maintain 60-65 mph without downshifting with the A/C on.

https://bbkperformance.com/collections/throttle-bodies/products/jeep-4-0-62mm-throttle-body-91-03
 
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CharlesHS said:
Several years ago I was having problems with idle fluctuations and what appeared to be a lean idle miss...
After quite a bit of troubleshooting I discovered the throttlebody was drawing air in between the body of the throttlebody and the throttle shaft.
Researched a replacement and didn't feel confident purchasing one of those online refurbished parts so I looked into a new BBK 62 mm throttlebody.
Once I decided that BBK was the one I found a 25% off SALE on one.
I disconnected the battery ground lead while installing (ECU reset for air/fuel calibration); upon startup the ECU had to adjust idle RPMs.
Went for a drive for 45 mins and the increase in throttle response was quite noticeable.
There is a steep bridge on the way to the JAX airport that required me to downshift to 4th with the A/C on to maintain 55 mph; now I can maintain 60-65 mph without downshifting with the A/C on.

https://bbkperformance.com/collections/throttle-bodies/products/jeep-4-0-62mm-throttle-body-91-03
Click to expand...

I put a 62mm BBK TB on just long enough to see how bad the butterfly shaft bearing seals leaked during testing. The larger mouth makes it feel like it’s doing more without needing to push the pedal as much, and that’s about it.

I got a spare stock TB from eBay that I did the same o-ring mod to. I swapped them at some point for the heck of it and noticed zero difference in how they performed.
 
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MikeE024 said:
I put a 62mm BBK TB on just long enough to see how much the butterfly shaft bearing seals leaked during testing. The larger mouth makes it feel like it’s doing more without needing to push the pedal as much, and that’s about it.

I got a spare stock TB from eBay that I did the same o-ring mod to. I swapped them at some point for the heck of it and noticed zero difference in how they performed.
Click to expand...

So you returned the bbk?,I think I have the part number for bearings,but if the shaft is worn it won’t do any good.
 
Moglocker said:
So you returned the bbk?
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Yes I returned it to Oreillys the next morning.

Moglocker said:
I think I have the part number for bearings,but if the shaft is worn it won’t do any good.
Click to expand...

I don’t remember seeing any notable wear on either TB’s butterfly shafts. I bought new bearings as well, but I’m in no rush to dig the old ones out.

The oring mod leaves the bearing cages installed, and you use a 90* pick to remove the old hardened seals. Then install the slightly lubricated orings in their place. I chamfered the edges of the flat part of the butterfly shaft so it wouldn’t cut the orings during install. No negative effects from doing so since the flat end simply slots into the TPS sensor.

I may install the new bearings when the orings eventually need to be replaced, but the new seals look so tiny that I wouldn’t be surprised if they don’t seal well (much like my experience with the BBK).
 
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MikeE024 said:
The larger mouth makes it feel like it’s doing more without needing to push the pedal as much, and that’s about it.
Click to expand...

Throttle bodies are just air restrictors/metering devices. Assuming two throttle bodies are capable of flowing the required amount of air, the larger one will simply flow the air at a lesser % opening.
 
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