Author Topic: 4.0L TB SWAP AIS housing question  (Read 4041 times)

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Nicks92jeeper

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Re: 4.0L TB SWAP AIS housing question
« Reply #15 on: September 16, 2011, 09:44:21 PM »
I believe that I used the 2.5 housing. I tried the 4.0 but my rpms were at about 4500 rpm and I though that was a bit dangerous. So I used the 4.0 throttle body with the 2.5 sensors and AIS housing. This was last year that I did this mod and my brain is shot right now. I would basically say try the 2.5 housing with the 2.5 sensors. If that doesn't work then try the 4.0 housing. Make sure that you have a good seal as well so no intake leak.
« Last Edit: September 16, 2011, 09:46:56 PM by Nicks92jeeper »

Nicks92jeeper

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Re: 4.0L TB SWAP AIS housing question
« Reply #16 on: September 16, 2011, 09:54:14 PM »
Found a picture and I took everything off the 2.5 and put it on the 4.0. This picture also shows how much you will gain if port math or whatever with the intake manifold to match the TB. It would be a noticeable difference in my opinion. The 2.5 is on the left and the 4.0 is on the right. the second picture shows a faint line of the potential size it could open up to. the third is opened up. I used a drum sanding bit in my drill press and it made fast work since the intake was out.

Offline sharpxmen

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Re: 4.0L TB SWAP AIS housing question
« Reply #17 on: September 16, 2011, 10:22:19 PM »
Found a picture and I took everything off the 2.5 and put it on the 4.0. This picture also shows how much you will gain if port math or whatever with the intake manifold to match the TB. It would be a noticeable difference in my opinion. The 2.5 is on the left and the 4.0 is on the right. the second picture shows a faint line of the potential size it could open up to. the third is opened up. I used a drum sanding bit in my drill press and it made fast work since the intake was out.

that's not a 4.0 on the right btw, it's a bored out 4.0, the stock one tapers on the bottom (similar to the 2.5 but larger diameter) - the machining job is not that great but at least whoever did it stopped before the butterfly to prevent getting it out of spec when the throttle is closed - you got a bored out t/b to 60mm for $15 which is a really good deal.
'95 YJ, NSG370 6spd / Hurst shifter, Dana 300 + 4:1 Doubler / tri-stick, Custom skid, Super D35 / Auburn LSD / 4.88, 35x12.5x15 BFG KM2, 64mm t/b, 1.7 RollerRockers, MkVIII e-fan, Dual Diaph Booster
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Nicks92jeeper

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Re: 4.0L TB SWAP AIS housing question
« Reply #18 on: September 17, 2011, 11:44:28 PM »
Actually I bored it out with the drum sander on a drill press and just wanted to get it good enough. You gunna make me cry! I bored it out a bit on both ends and after this picture I smoothed out the sides so they were smoot and consistant. I like the fact that you noticed though!
« Last Edit: September 17, 2011, 11:46:17 PM by Nicks92jeeper »

Offline sharpxmen

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Re: 4.0L TB SWAP AIS housing question
« Reply #19 on: September 18, 2011, 01:38:12 PM »
Actually I bored it out with the drum sander on a drill press and just wanted to get it good enough. You gunna make me cry! I bored it out a bit on both ends and after this picture I smoothed out the sides so they were smoot and consistant. I like the fact that you noticed though!
that's actually a pretty decent job for first time and on a drill press

reason i notices is b/c i made a few myself :lol: bored out to 64mm
turned out like this (last ones i made, i busted a few trying to get largest bore but neve been able to go past 64mm)





(not trying to sell them, have none at the moment - just in case someone will think i'm pimping them out)
'95 YJ, NSG370 6spd / Hurst shifter, Dana 300 + 4:1 Doubler / tri-stick, Custom skid, Super D35 / Auburn LSD / 4.88, 35x12.5x15 BFG KM2, 64mm t/b, 1.7 RollerRockers, MkVIII e-fan, Dual Diaph Booster
Latest: Corbeau BajaRS heated seats :dance: keeping warm the rear end

Offline bukdwn

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Re: 4.0L TB SWAP AIS housing question
« Reply #20 on: September 18, 2011, 08:23:51 PM »
Here's what i ended up doing. I removed the 2.5L housing and re-installed the 4.0L housing. The 2.5L housing on the 4.0L TB did not idle the best.  The idle would take a little longer to come down to normal idle. Everything in this jeep has been changed as far as a full tune up. The engine runs like a top! At cold start up, the TB with the 2.5 housing would be around 17 to 1800 RPM's. With the 4.0 TB housing installed the cold start is around 18- 1900 RPM's.  I need to install a new air filter system, i can tell with the stock air box top unclipped  for straight threw air, that it comes up in rpm's a little faster.    So, if your having problems with your idle with this mod, try installing the 4.0L  housing!  Thanks for all the info and the fact's forum! i really appreciate it.
95 YJ  2.5

Offline sharpxmen

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Re: 4.0L TB SWAP AIS housing question
« Reply #21 on: September 18, 2011, 08:56:39 PM »
how's your air filter? also, do you have lot of blow-by?
'95 YJ, NSG370 6spd / Hurst shifter, Dana 300 + 4:1 Doubler / tri-stick, Custom skid, Super D35 / Auburn LSD / 4.88, 35x12.5x15 BFG KM2, 64mm t/b, 1.7 RollerRockers, MkVIII e-fan, Dual Diaph Booster
Latest: Corbeau BajaRS heated seats :dance: keeping warm the rear end

Offline bukdwn

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Re: 4.0L TB SWAP AIS housing question
« Reply #22 on: September 18, 2011, 09:15:23 PM »
SHARPXMAN, As far as the air filter, I have the stock air box and filter. The filter has been changed in the last 300 miles.  forgive me but i'm having a brain fart!  What exactly do you mean buy blow buy?
95 YJ  2.5

Offline dwtaylorpdx

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Re: 4.0L TB SWAP AIS housing question
« Reply #23 on: September 18, 2011, 10:35:08 PM »
Blowby is the gases coming from the crank case. (Usually from around the rings)
If the crankcase vent is plugged (Small brass fitting on valve cover) it will blow a
lot of vapor where it does not belong. Which will gum up the IAC and the passage it sucks through.

Dave
94 YJ - 2.5 Hesco Cam B&B Ported - AX5 Trans w/Centerforce Dual Friction Clutch - 4" Rough Country Lift W/Skyjacker Shocks - D44 Rear/ARB - D30/ARB - ARB Compressor - Warn M8000 in Custom Bumper - Reunell Rear Bumper - Metalcloak 6" Body Armor Kit - Tuffy Console - 265x85-16 Tires - 2M Radio

Offline sharpxmen

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Re: 4.0L TB SWAP AIS housing question
« Reply #24 on: September 18, 2011, 10:49:02 PM »
Blowby is the gases coming from the crank case. (Usually from around the rings)
If the crankcase vent is plugged (Small brass fitting on valve cover) it will blow a
lot of vapor where it does not belong. Which will gum up the IAC and the passage it sucks through.

Dave

correct, will also mess with your idle that's why i asked (and that's regardless if the small vent is plugged or not, too much and will blow thru both).
'95 YJ, NSG370 6spd / Hurst shifter, Dana 300 + 4:1 Doubler / tri-stick, Custom skid, Super D35 / Auburn LSD / 4.88, 35x12.5x15 BFG KM2, 64mm t/b, 1.7 RollerRockers, MkVIII e-fan, Dual Diaph Booster
Latest: Corbeau BajaRS heated seats :dance: keeping warm the rear end

Nicks92jeeper

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Re: 4.0L TB SWAP AIS housing question
« Reply #25 on: September 19, 2011, 03:04:48 AM »
When I did the head gasket I examined everything to see if there was any blockage and the vents in the valve cover was completely clogged so I opened them up again. The reason I looked was the air filter was coated in oil so I knew something was clogged up but I didn't notice anything on the idle as I did a lot of mods at this time.

Nicks92jeeper

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Re: 4.0L TB SWAP AIS housing question
« Reply #26 on: September 19, 2011, 03:06:33 AM »
@ Sharpxmen. Those are some real pretty Throttle bodies! You did a very good job on boring them out.

Offline Bounty Hunter

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Re: 4.0L TB SWAP AIS housing question
« Reply #27 on: September 19, 2011, 02:26:15 PM »
Your high idle at startup sounds like it has nothing to do with the IAC, but more likely a vacuum leak.  It comes down as the IAC adjusts for the vacuum leak in an attempt to correct the high idle.

Really, you should prolly run the 2.5L IAC housing and plunger.