Topic: Installed a 4.0 TB Check Engine light now on

[Moondo]

I had to replace an exhaust manifold stud this weekend so i figured it would be a good time for the 4.0 throttle body upgrade. I used all of the 2.5 TB components and I have double/triple checked all of my connections. After install I disconnected the battery and let it sit overnight. The jeep idles just fine but there is a slight hesitatition when I really get on the excelerator. Should I continue to disconnect the battery to try and reset or did I miss something?     

[jcsanders79]

What code is it throwing?

[sharpxmen]

What code is it throwing?

x2.
also make sure you didn't mess the vacuum lines. Could be the tps too (from the hesitation you describe), but since it was running fine before it's unlikely

[Moondo]

I will be installing a Supertrapp exhaust next week I will check the codes at that time. In the meantime I will check vacuum lines and TPS.

[justin399]

Make sure you swapped the AIS housing to, this is the piece that the AIS sensor bolts into. I swapped the sensors but not this housing and had troubles. Good luck.

[jcsanders79]

Just wondering if you bored the intake out to 62mm?

[sharpxmen]

Make sure you swapped the AIS housing to, this is the piece that the AIS sensor bolts into. I swapped the sensors but not this housing and had troubles. Good luck.

what's the AIS housing? are you referting too idle control valve? (i don't know what AIS is - just curious)

[justin399]

Check this out from Jeffy: http://4bangerjp.com/forums/index.php/topic,8.msg8.html#msg8
Look at where the AIS motor bolts in, thats the housing. When you swap the throttle body you've got to use the 2.5L sensors and that 2.5L housing. I hope this helps.

[sharpxmen]

Check this out from Jeffy: http://4bangerjp.com/forums/index.php/topic,8.msg8.html#msg8
Look at where the AIS motor bolts in, thats the housing. When you swap the throttle body you've got to use the 2.5L sensors and that 2.5L housing. I hope this helps.

yeah, that's the idle valve - i didn't know it's called AIS, seen it as IAC (idle air control) - good to know that is also called AIS (air idle ?something? i assume), but that's correct you need the motor and the housing.

[dos0711]

Actually, no you don't. I used a 4.0 throttle body as is. The only problem I had was it was a tad slower to come down to idle. That being said, on my 2nd TB swap I did use the 2.5 IAC but if I were to do it again, I'd prbly leave it 4.0 as it didn't make a huge difference. When I initially started up the complete 4.0 the idle raced up to about 3k for about 20 seconds. But after that, the pcm brought the idle down to normal.

[Moondo]

I didn't bore it out to 62MM and I used the AIS housing as well as sensor. I have been driving it everyday for the past two weeks since I did the swap and I noticed that I was gaining pickup and the hesitation went away just this past weekend but the light remained on. Well, Last night I stopped to pick up another can of throttle body cleaner. I planned on taking the TB apart again and go through all of the sensors and make sure everything was tight with no leaks. When I started the jeep to leave the store the light was off! When I came into work this morning it was still off... Now I am wondering if I had a piece of crud or something when I originally did the swap. Do I go ahead and pull it apart or just drive it?     

[neale_rs]

I vote for just driving it if it is working fine.

[sharpxmen]

we still didn't hear what the code is so it could be unrelated (like o2 for example)

[Moondo]

I didn't get a chance to check the code out. I will get that done and post it.