4.0 replacements and upgrades
CF Veteran
Joined: Jan 2012
Posts: 1,057
Likes: 2
From: Nazareth/Pen Argyl, Pennsylvania
Year: 1989
Model: Cherokee
Engine: 4.0L 242ci I6
If you look at the stock air box, the air comes in from right behind the headlight/grill. Thats cold outside air. Also, look at the box itself. It's basically a box with a tube coming out and a filter in the middle. It's not a very restrictive intake system if you think about it. The air doesn't come from inside the fender and go through 4 different boxes and passageways before it hits the engine like some other vehicles. With the price of a CAI for our renixes and the way they are designed, it's not really worth it IMO. I can hear my intake sucking pretty good over the sound of my muffler. I think it's fine. I agree on a larger throttle body though. That would definitely free it up. Add a better flowing filter and its good for me!
Member
Joined: Feb 2012
Posts: 183
Likes: 0
From: Springfield, Missouri Area
Year: 2000
Model: Cherokee
Engine: 4.0
Originally Posted by cruiser54
60mm throttle body from www.strokedjeep.com.
Have your exhaust pipe re-done without the "crush" and re-routed as necessary.
Get some rebuilt 4 hole injectors from some of the guys on this forum or www.precisionautoinjectors.com.
Have your exhaust pipe re-done without the "crush" and re-routed as necessary.
Get some rebuilt 4 hole injectors from some of the guys on this forum or www.precisionautoinjectors.com.
Member
Joined: Feb 2012
Posts: 183
Likes: 0
From: Springfield, Missouri Area
Year: 2000
Model: Cherokee
Engine: 4.0
Originally Posted by 2000XJOffRoad
There is a guy on this for that I got a TB 60MM And he charged 80 and if you send the old TB back he will give you 25 back. It works great and is well built. There is also another guy that sells the 4 hole injectors for I believe it was 60 and I just ordered them should get them this week.
Thread Starter
CF Veteran
Joined: Sep 2011
Posts: 10,447
Likes: 0
From: Frederick, MD
Year: 1989
Model: Cherokee
Engine: 4.0
Originally Posted by XJ.89.Limited
If you look at the stock air box, the air comes in from right behind the headlight/grill. Thats cold outside air. Also, look at the box itself. It's basically a box with a tube coming out and a filter in the middle. It's not a very restrictive intake system if you think about it. The air doesn't come from inside the fender and go through 4 different boxes and passageways before it hits the engine like some other vehicles. With the price of a CAI for our renixes and the way they are designed, it's not really worth it IMO. I can hear my intake sucking pretty good over the sound of my muffler. I think it's fine. I agree on a larger throttle body though. That would definitely free it up. Add a better flowing filter and its good for me!
Thread Starter
CF Veteran
Joined: Sep 2011
Posts: 10,447
Likes: 0
From: Frederick, MD
Year: 1989
Model: Cherokee
Engine: 4.0
Originally Posted by cruiser54
Whoever, on this forum, is selling the injectors and throttle bodies needs to respond to this thread!!!
Senior Member
Joined: Oct 2011
Posts: 731
Likes: 0
From: St. Albert
Year: 1989
Model: Cherokee
Engine: 4.0L I6
Firstly- The dealership wants about $130 per injector where I am located. I would agree that precisionauto is quite fair. Second, for 2000XJOFFROAD, "Thexjflies" only bores the throttle bodies for the high output (91'+) engines, so (if you choose to do this upgrade) you will need an alternate source such as www.strokedjeep.com. Third, no you do not have to take the valve cover off. It is not a difficult job, especially if you have the factory service manual. Also, it is worth noting (you will see what I mean when you swap these) that you do not have to disconnect the fuel lines from the fuel rail. The FSM says to do this, but it is easily avoidable, and saves some time, mess, and money. 
Ive had to do it twice now, so I figured I'd share here. Good luck!
Ive had to do it twice now, so I figured I'd share here. Good luck!
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,579
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
60mm throttle body for a Renix $90 exchange. www.strokedjeep.com.
Bolts right on. The manifold opening is already 60mm. Easy.
Bolts right on. The manifold opening is already 60mm. Easy.
Thread Starter
CF Veteran
Joined: Sep 2011
Posts: 10,447
Likes: 0
From: Frederick, MD
Year: 1989
Model: Cherokee
Engine: 4.0
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,579
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0