Are 2.5L and 4.0L throttle bodies the same?

[redyouch]

hey, just wondering if a 2.5L and a 4.0L throttle body are the same thing. thanks

[seanR]

No, I think the 4.0l TB is larger dia. that the 2.5.

[Eagle]

hey, just wondering if a 2.5L and a 4.0L throttle body are the same thing. thanks
What year are you asking about?

[Ghost]

Need to know the year like Eagle said. But in 91 the outside machining started to be standard they just changed the inside diam. on the two. I just posted on the Modified board about this. I put a 4.0L TB on my 2.5L Saturday.

[redyouch]

its from a YJ. if i were to bore it out, would it work out the same as a regular 4.0L throttle body??

[asatxj]

its from a YJ. if i were to bore it out, would it work out the same as a regular 4.0L throttle body??
I have one from a 97 xj I'll sell you for $75 shipped

[redyouch]

i dont need any, im trying to get involved in a throttle body boring venture. i have 4 that i got for alot less than $75. total. thanks anyway. back to the main question, will a YJ 2.5 throttle body be able to be bored out to 62mm? thanks

[jeepguy97]

Why don't you try to bore it out to 62mm and tell us. Seems like you have enough laying around to do so.

[redyouch]

Why don't you try to bore it out to 62mm and tell us. Seems like you have enough laying around to do so.


your remarks arnt necessary in this thread, you are not helping out at all. i would expect a better responce here on naxja. this isnt JU...

[Ghost]

First off I put a stock 4.0L on mine. The only difference in the TB 's is the inside bore. Could you bore a stock TB out? Yes. Would it be cost effective? Don't know. Would it be as benificial as teh stock 4.0L? Yes if you bored the whole thing to the same size as the 4.0L including the butterfly. The TB's are tapered. Most boreing is nothing more than the bottom half below the butterfly. The 4.0L one I put on my 2.5L is bigger all the way through. Which is why I say that I believe it has given me more power than jsut boreing the stock one.

[redyouch]

thank you for your help

[Brian Felts]

check out this months write up in JP magazine there is a write up about putting the 4.0 TB on the 2.5. :us:

[jfw432]

I'm trying to do the same thing because some jack hole sold me a 2.5L TB instead of a 4.0L. I noticed the IAC was different. Whether they work the same or not is beyong me but they look different anyway.

[Ghost]

the sensor is different and so is the removable piece that is bolted to teh TB. THe secruity torx screws are very fragil and lock tight was used. Heat them b4 trying to remove them. You will need to swap that piece from teh 2.5 to teh 4.0 one.

[old_man]

There is a 4bangers group on Yahoo forums that deals strictly with that 2.5L. This has been covered tons of times over there. I don't remember the answer right off hand. There is also a guy that is selling the eliptical throttle butterfly you will need if you bore it out.

I built a 2.5L from carbed to TBI injection with a cam and headers. I didn't see the necessity to bore the TB for the trails I was running. It might have helped on the highway at more open throttle positions, but without helping the exhaust to flow better with porting and headers, as you know, you will be most likely wasting your efforts.

For those who are reading this that are not familiar with this, the early 2.5L's had throttle body injection. In other words, they only had one injector. The later throttle bodies look a lot more like the ones on the HO 4.0L and there is an injector per cylinder.