Jerry, perhaps you can confirm or deny this...I've never so much as looked under the hood of a Jeep with an auto tranny and I'm far from a mechanic (all book knowledge from reading the experts' posts on forums) so this may not even be plausible.
On my old Dakota, there was a TV cable (aka kickdown cable) for the tranny hooked to the throttle body which would control both upshifts and downshifts...to an extent. What is the likelihood that either the tb spacer slightly changed the length of that kickdown cable causing it to be out of adjustment, or that it was knocked out of adjustment while working on it. Or is this cable not even present on the Jeep transmissions?
Originally Posted by jeepjones
My mods worked good so I really have no idea why you guys keep telling people not to do any to the 4.0?
They're not saying don't mod the 4.0...they're saying don't waste your money on these specific useless mods on the 4.0. The Jeep's stock intake flows more than enough air for the engine to handle so increasing airflow is useless since they engine CAN'T take anymore in. On the 4.0, throttle body spacers are nothing more than an oversize paperweight. A bigger throttle body would probably help some as mentioned above...although you do need to be careful. If you go TOO big, your low end torque will start dropping off. Can't remember the reason why but it was a big issue for V6 Dakota owners who were putting V8 throttle bodies on their trucks. Stock on the Dakota was like 42mm...going up to 46 or 48 helped tremendously in low end torque, acceleration, and top speed. Going over 50mm caused a lot of people to notice bigger changes in the top end, but their trucks lost low end torque and bogged down off the line. Once they got into the powerband though, they could feel them really start to take off. Even with a larger throttle body, I don't think a new intake would be necessary...the stock one probably could flow more than enough air even for the new throttle body to handle.