TOPIC: 1999 Jeep Cherokee Sport_Idle Air passage issue

I'm looking to groove this '99' Jeep Cherokee Sport automatic 4.0 Ltr.
However, I'm not sure how exactly to deal w/ the gaping ports on both sides of the throttle plate.
Block them both? I recall everyone saying to re-route the porting on the 'Engine' side. But what to do on the air intake side?

I have one of these on my bench right now, and will be taking a short video (you may find one on GroovyServiBulletins - YouTube ) showing what can be done.

Don't worry about the other side, JV. Only what happens after the throttle plate matters, my friend.

Ron

JV here is my experience w/ pics of basically same TB



Might save ya some time.

Tracy G

Hey JV,

I did my 98 Jeep Cherokee 4L, and to second Tracy, you block off the lower rectangular opening, drill through it and channel out air passages on either side to just over the throttle-plate axle. The important thing is to carefully mark where the gasket sits, as there is not much room for error before you cut beyond the gasket sealing area. As I live in more northern and colder climes, I made my channels as deep as possible in order to get as much air as possible on those -20 to -30 mornings. As is happened, it used to have a start up idle of 1200 rpm in cold weather for the first number of seconds/ minute before idling down, now it has a start up idle of around 700 - 900 rpm down to around -30C. After about -35C, it won't sustain an idle without some foot pedal assistance for the first minute, and then it will idle at 700-900 rpm. I use full synthetic, 5w-30 in winter so the oil is very viscous even below -35C. The dog occasionally runs across the cord and unplugs the block heater, so I have some starting leverage.

Good luck!
Luke

Thanks for the support guys, I'll be looking forward to seeing that video Ron!

GadgetmanSaskatchewan wrote: Hey JV,

I did my 98 Jeep Cherokee 4L, and to second Tracy, you block off the lower rectangular opening, drill through it and channel out air passages on either side to just over the throttle-plate axle. The important thing is to carefully mark where the gasket sits, as there is not much room for error before you cut beyond the gasket sealing area. As I live in more northern and colder climes, I made my channels as deep as possible in order to get as much air as possible on those -20 to -30 mornings. As is happened, it used to have a start up idle of 1200 rpm in cold weather for the first number of seconds/ minute before idling down, now it has a start up idle of around 700 - 900 rpm down to around -30C. After about -35C, it won't sustain an idle without some foot pedal assistance for the first minute, and then it will idle at 700-900 rpm. I use full synthetic, 5w-30 in winter so the oil is very viscous even below -35C. The dog occasionally runs across the cord and unplugs the block heater, so I have some starting leverage.

Good luck!
Luke

Thanks for the valuable info Luke! It's great to know because the Jeep I'm looking at is in a fairly cool climate too.