Author Topic: installed 4.0TB and spacer  (Read 1354 times)

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Offline bestos

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  • Posts: 129
installed 4.0TB and spacer
« on: November 24, 2012, 09:18:25 AM »
got my 4.0 throttle body on wednesday, installed it wednesday night along with the spacer i bought 2 weeks ago.  just some info for people who do this.

the TB i got had both sensors still attached.  here is what i did wrong first time around.

i took IAC sensor off 4.0 and put the 2.5 sensor in the existing 4.0 housing.
kept existing TPS sensor of 4.0 on because i couldnt get the 2.5 sensor off my current TB
put it all on motor with spacer and started it up - 3,000 rpm STEADY cranking. 

So, i took it all back off, worked real hard and got the existing TPS of the 2.5L off and then on the new 4.0 TB.
THEN i took the IAC housing off the 2.5L and looked at it.  I noticed when messing with things that the 2.5L IAC sensor is smaller than the 4.0L sensor, so i realized the IAC housing guts have a bigger hole in the 4.0, SO air was passing the IAC sensor - i think that was causing the 3,000 RPM scream, SOOOOOOOOOOOOOOOOO

best practice is to take the 2.5L IAC housing, 2.5L IAC,  2.5L TPS on the new TB and life will be good - maybe im the only idiot who screwed that up, but just incase, someone else can learn from it, i hope it helps.

ALSO, IMPROVEMENTS ARE:

i notice a "small" increase in accel power from rest to 2,500 RPM, the real increase for me was 2,500 to 3,900 RPM.  MUCH MUCH stronger at that RPM band. which is good for me at my 32" tires and 4cyl, i need to wind it up that far when getting on to Onramps or joining highway traffic, i needed that bad, mine would bog done at those RPMS and it does not do it at all now!! i do like the mod a Lot.

I am getting my busted rear exahust stud taken out MONDAY, life will be great then in my 4banger!!

oh, i did not use the Throttle cable bracket relocation, would not work on the 4cly setup, just hooked the cable back up.



Offline neale_rs

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  • Posts: 3583
Re: installed 4.0TB and spacer
« Reply #1 on: November 30, 2012, 11:27:55 AM »
Looks like you got some great results.
'95 YJ, 33 x 12.5 mud tires, RE 4.5 ED lift, Atlas 4 speed, rear D44, ARBs front and rear, 4.56 gears, 8000# winch

SDWE61988

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Re: installed 4.0TB and spacer
« Reply #2 on: December 05, 2012, 06:21:11 AM »
best practice is to take the 2.5L IAC housing, 2.5L IAC,  2.5L TPS on the new TB and life will be good - maybe im the only idiot who screwed that up, but just incase, someone else can learn from it, i hope it helps.

You are not the " Only Idiot" to run into this problem.  I am a fellow idiot who did the same thing.  I still need to change the housing on mine if I can find one.  I think I got rid of my old TB.  I have to take some time and look though the pile of "spare parts" to see if it is still around.   :brick:
« Last Edit: December 05, 2012, 02:51:17 PM by Jeffy »