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Forum namePerformance/Engine
Topic subjectHere Is Some Additional Info About Jeep TB's (How I Did The Conversion)
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i5&topic_id=109072
109072, Here Is Some Additional Info About Jeep TB's (How I Did The Conversion)
Posted by teklein, Jun-22-08 07:17 AM
Hey,

The original write up is here, some things I did are different:
http://www.2gnt.com/?d=60mm_Jeep_Throttle_Body

Im modding a Jeep 60mm TB from the mid 90's 4.0L Cherokees to fit on my Mitsuneon! It actually necks down to 55mm at the bottom, but that is easily remedied (which I did not do yet, waiting to sandblast my IM that im porting out). 55mm is still a HUGE improvement over a 49mm TB that comes stock. 6mm may not seem like much, but remember that the area of a circle is exponential. Going from a 49mm to 52mm TB on my DOHC Neon was a great mod, so I have high expectations for this one!

I already did a bunch of work to the body of the TB like cutting two of the bolt holes off, taking a few pieces off of it, etc. I do not have any pictures of this because I actually started the TB two years ago when I had a Neon ACR!

The only parts from the Jeep TB I used are: body, butterfly plate, IAC tip.
Parts from the Eclipse TB is: Sensors, throttle shaft.
The spring is actually coming from an old Neon, because it fits better than the Eclipse or Jeep IMO. But all three work great!

Here is a picture what a stock Jeep TB looks like:


Here is my modded TB body (left) with a stock 420A TB on the right:


Here is a close up of my TB body (the red area is what I need to cut off to allow clearance for the throttle shaft). Also, if you notice the empty bolt hole to the left in the red area, that is the old shaft stop screw for the Cherokee, it needs to be moved to the other side for the Eclipse shaft. Took five minutes:


Here is the Eclipse IAC with a Jeep tip on it, this allows it to seat correctly inside of the idle air passage on the TB:


And here is the Eclipse throttle shaft, notice I had to cut material from the spring perch for the butterfly plate holes to center in the TB. I still need to widen the shaft slot to fit the 60mm plate in:


Thats it for now! I gotta run to ACE for some more Dremel cut off wheels, a washer, and a plug for the manifold. Ill update with more pics later today!

Thanks for reading!
109073, RE: Here Is Some Additional Info About Jeep TB's
Posted by teklein, Jun-22-08 07:18 AM
K, here is the Eclipse throttle shaft. I cut some material away from the spring perch on the edge to hold the spring better. Also, the shaft slot has been widened to 60mm using a Dremel, and a small bastard file.


Here is the gasket I made using gasket material, and a plug I bought from ACE to fit the existing idle air passage on the Eclipse IM. It is a half inch button plug (I think thats what they call them). It has metal tabs on the back that hold it in place. I took a hammer to flatten it out on the IM. Ill put some RTV around it when it goes on the IM. Some people plug that hole with a rubber plug, but I dont want the chance of it coming off and entering the motor. The button plug has a 1/16 edge all the way around the hole. More secure IMO.


And finally, here she is! Ill put it on tonight or tomorrow.


NOTE: For the spring I ended up cutting one coil off the Neon spring and bending a tab to fit underneath. It was much neater this way and the tension feels the same.

When I move the throttle shaft it opens all the way, and feels really smooth. No snags opening or closing on the plate.

All in all I have thirty dollars in this, and about three hours. Not bad considering a 55mm TB made for the Eclipse is around 140-175ish.
109074, RE: Here Is Some Additional Info About Jeep TB's
Posted by teklein, Jun-22-08 07:18 AM
Alright, and here is the plug in the old IAC passage with some silicone for good measure. I know its dirty in there, but thats 248000 miles of build up! As soon as I find a sandblaster around here I will have my other IM sandblasted and ill finish opening up the neck to 60mm:


And here is the TB on the car!


First time I fired it up it idled at 4000 :shock:
So I pulled out the IAC and adjusted it a little more, and set the tension on the throttle cable. This time she idled, but I had a whistle that was random and it would hang at around 2k for a few seconds then return to idle. I drove it up to Advance to have the codes read (I always have the CEL on for the EGR) to make sure that the IAC or TPS was not messing up, they were fine.

So I brought it back home and pulled it apart. I took the vacuum line that ran to the TB off, and put it to an empty port on the manifold. Then I plugged the nipple on the TB. I also realized that the butterfly plate was upside down from when I first bought the Jeep TB (part number was normally on top) and I flipped it around. The butterfly plate made the biggest difference, I could tell that it seated better in the body.

Now it idles at 950+/- which is where its normally at, it does not hunt for idle every two seconds, goes right back to idle when coming to a stop, and best of all NO WHISTLE!

On a side note, I found this when I opened the hood and went to take the intake off! It cant fall on the ground because it is also supported by the splash shield and bumper. I read the warranty info online and AEM wont honor the warranty because I bought it used and I have no receipt :cry:

You can look at the way it came off, the whole weld all the way around basically came off :shrugs: Nothing even touched it and I have only removed it from my car once about two months ago.

Who can weld? It does not even have to look that pretty!
109075, RE: Here Is Some Additional Info About Jeep TB's
Posted by cs82685, Jun-22-08 03:27 PM
Very nice, no reason this can't also be wikified ;)
109077, RE: Here Is Some Additional Info About Jeep TB's
Posted by DarkOne, Jun-23-08 03:50 AM
Originally posted by cs82685
Very nice, no reason this can't also be wikified ;)


Agreed.

Also, the AEM's always break like that. the bracket is rather useless anyway, IMO.
109078, RE: Here Is Some Additional Info About Jeep TB's
Posted by teklein, Jun-23-08 04:28 AM
Originally posted by DarkOne
Originally posted by cs82685 Very nice, no reason this can't also be wikified ;)
Agreed. Also, the AEM's always break like that. the bracket is rather useless anyway, IMO.


Cool, im gonna see how much the welding shop wants to reweld the bitch, if not ill just seal the hole and call it a day. It really doesnt go anywhere anyway.

109081, RE: Here Is Some Additional Info About Jeep TB's
Posted by RoninEclipse2G, Jun-23-08 05:44 AM
Originally posted by teklein
Originally posted by DarkOne
Originally posted by cs82685 Very nice, no reason this can't also be wikified ;)
Agreed. Also, the AEM's always break like that. the bracket is rather useless anyway, IMO.
Cool, im gonna see how much the welding shop wants to reweld the bitch, if not ill just seal the hole and call it a day. It really doesnt go anywhere anyway.


JB weld the fucker and call it a day. it'll probably hold better than the factory weld.
109087, RE: Here Is Some Additional Info About Jeep TB's
Posted by teklein, Jun-23-08 07:58 AM
Probably right! lol. That weld was super shitty.

BTW, this is now in the wiki :)
109088, RE: Here Is Some Additional Info About Jeep TB's
Posted by DR1665, Jun-23-08 07:58 AM
Excellent write up. Much appreciated.