| 4.0L Throttle
Body Conversion |
|
| Well, for a while
now, I've been looking for something to put a little more umph back into
the 4 Banger.. I had heard through a few sources that a
Throttle Body from a 6 Cylinder (4.0) Jeep Wrangler ( TJ or YJ (after 91))
or Cherokee (XJ after 87) will fit on the 2.5L engine without any
modification and will give you some decent games for the money. |
 |
 |
So, I searched for a 4.0L Throttle Body everywhere.
Found that most junk yards simply didn't have newer jeeps at all, and most
of the newer ones they had had engine fires, and the few that were there
because of accidents not involving fire were the 4 Bangers...
|
| Here you can see
the differences in the top of the throttle bodies.. The one on the
left is the new 4.0L Throttle Body, and on the right (obviously) is my old
TB. |
 |
 |
Then I flipped the TB's over and discovered that the
openings on the bottom are larger as well. I have a PowerAide
Throttle Body Spacer (as you can see in the pic below (red)) for the 2.5L
engine. As you can see on the bottom of the old TB the spacer is
actually made for the 4.0L. You can tell by that enlarged circle of
"grudge". So, after you get the new TB you need to clean
it up some. Just take a Scotch Brite Pad and clean the whole thing
well. Then, if your TB didn't come with the AIS motor and other
sensor (forget what that one is) you will have to remove those off of the
old TB. These are the plastic black objects on the top of this
photo. |
| Here you can see
the Red Throttle Body Spacer. I had just put new gaskets on there,
so I skipped this step. But if you haven't done this, carefully
examine your old gaskets, and if they are cracking, or just looking old,
get some new ones to put in there. |
 |
 |
Now that you've taken the old TB off, replaced the gaskets
if needed, and cleaned up the new TB, just plop the new TB right where the
old one was. All the bolts are the same, and in the same spot and
the throttle cable is exactly the same. This is a very easy
install. I decided to keep the stock air-box for right now because
of funding issues, but will eventually go to an air-tube with a K&N
Conical Filter. |
| The next step is to
start the Jeep up to make sure everything is working okay. At first,
the RPM's will run around 2500, but they will start to come down as
everything gets adjusted. If they don't come down after about 5
minutes, that means that there is something wrong with one of the
sensors. Just take the TB back off (after you shut the Jeep off) and
blow everything out and clean those up some more. Then, here's the
good part. I waited until the idle was about 500 rpm's (where it was
before) and took it for a spin. As I was driving to the exit of the
apartment complex I noticed that first felt like it had more "umph"
to it. Not a whole lot, but enough to definitely notice. Then
pulling out, I had to gun it to merge into traffic. Man, I
definitely noticed a difference there. Shifting was more solid, and
I found myself shifting sooner than before. With a 4 Banger, stock
gears (4.10's), and 33" tires its great to have some more
power. I found that I could now gain speed in 5th when doin about 50
mph. It wasn't a quick acceleration, but I could actually use 5th
again. This was on flat highway though, so going uphill would
definitely require up-shifting to 4th. Also, I was goin about 45 mph
and shifted to 4th (would have been too low before) and I could
accelerate. I will be closely monitoring my fuel mileage, and report
on here my findings. I think it will increase because of being able
to shift sooner, and not have to floor it just to get going.
If you have any questions or comments, please email me at tragedyeric@yahoo.com
and I'll try to help out as much as I can....
eric |
|
