Topic: 4.0 throttle body question..like or dislike

[dunklervogel]

Did you reset the computer?  You'll see performance increase more after you drive it more as the comp adjusts.

[jimj]

Tell me how was the port match between the TB to TBS to Intake maniflod.
I sure like my smooth tbs & 4.0L TB  great mod with The Banks Header.

This is the amount of overlap between the 4.0 TB and my 2.5 intake. I'm going to pull the intake and port match the TB inlet on the manifold and the ports at the head, but that will have to wait till the daytime temps drop well below the 110 mark, maybe September when it cools off. 

[Dare2BSquare]

Did you reset the computer?  You'll see performance increase more after you drive it more as the comp adjusts.

Yes, I kinda had to. I ran seafoam through the intake before I made the swap and my check engine light came on. So I reset the computer after I did the swap.

[kenandtj]

well i did it, i picked up a 4.0 tb on ebay for 30.00 not bad considering i was going to spend 75. first off i must say it was probably the simplest thing i have done yet. it took me 30 min to swap it all out and put it back in. from what i can tell it seems a little snappier of the line. i am going to drive it today and get a base line of how it is.then tomorrow i am going to hone out the intake to match and then see how much that adds. i also have a set of headers waiting for me to free up time to put in. thanks to everyone who had something to say.....ken

[Jeffy]

I got my 4.0L TB from a salvage yarfd for about $30, and a TBS (62mm) from eBay for something similar to that (dont remember exactly how much it was).  When I installed both, the idle RPM's would not come down from 1,500, so after a couple of days of this (I figured that the computer had not adjusted before that), I took off the TB and left only the spacer.  Maybe my TB had some problems (I used the sensors from my 2.5L TB, so I know it was not that).  In any case, for me, it did not work.  And I would not advise you to pay $75 for that, as they can be found cheaper on eBay or by looking in a salvage yard.

By the way, JP had an article about the performance gains of putting a ram air type intake.  Check it out at:
http://www.jpmagazine.com/techarticles/engine/154_0706_jeep_wrangler_tj_intake_dyno/index.html

Felipe

#1 cause of high idle is a vacuum leak...  It gets asked a lot here.  Not only are you supposed to swap sensrs but also the IAS housing.  Otherwise, you'll get a vacuum leak there too.