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Topic Review (Newest First)
03-23-2013 11:28 AM
jonothehut
Quote:
Originally Posted by Sandstorm95 View Post

Glad it worked ! It took me punching in my center console before I realized I didn't swap it out lol
I was about at that point. Instead I slapped myself in the head for missing the iac housing.
03-17-2013 02:26 PM
Dac7529 As said in prior post you do have to swap the sensors but as far as the iac you have to use the 2.5l the housing for it as well. Haven't done the 19lb injectors but want to.
03-17-2013 02:01 PM
Sandstorm95
Quote:
Originally Posted by jonothehut View Post

Sandstorm95, that totally worked. Swapped out the iac, reset the ECM, started right up with no issue. I can't believe I missed that. Thanks man.

When I do start it up it does sit around 2000rpm then slowly works its way down to around 1000rpm. Doesn't seem to be any issues though.

Sorry for the 3rd post in a row. I can't find how to edit a post.
Glad it worked ! It took me punching in my center console before I realized I didn't swap it out lol
03-13-2013 06:14 PM
jonothehut
Quote:
Originally Posted by Gunz n tractorz View Post
What's the iac?
Quote:
Originally Posted by AZ_Zoner View Post
Idle Air Control valve. Looks like this.

cb

EXACTLY! Took me a while and tons to searching to figure I had to swap that out too.
This thread helped me out a lot. But I didn't have a MAP sensor. Not sure if yours does.
Cleaning IAC and Throttle body write up (for dummies) - JeepForum.com

EDIT: ActuallySandstorm95's post is what ultimately lead to me figuring it out
03-13-2013 04:37 PM
AZ_Zoner
Quote:
Originally Posted by Gunz n tractorz View Post
What's the iac?
Idle Air Control valve. Looks like this.

cb
03-13-2013 04:02 PM
ThePhantomPatriot Just got my YJ back from the shop, sound beautiful now, she purrs when on the throttle and is quiet when idling, no longer sounds like a boat. My exhaust header was leaking since the Jeep factory didn't put a gasket between it and the block. And I had a radial fracture at the flange of the down pipe which went over 180^ around and had a good half inch gap.

Since I can drive it again the engine starts at 2500rpm and is idling at 1500-1700rpms and when I shift I have to ease into gear and then get on the gas because it is idling too high. Also when I barely have my foot touching the peddle it is very touchy and will jump 500-1000rpms with very little pressure. I swapped out the sensors too, but not the IAC housing, was that supposed to be swapped too?

Questions:
1- Do I have to adjust the idle, or will the computer relearn the proper setting for the correct idle?
2- Once the engine learns the new setting will it have to relearn when I unplug the battery to do work and then plug it in once I'm done (resetting computer)?

Thanks.
03-12-2013 08:14 AM
ThePhantomPatriot I swapped mine this past weekend, but haven't had a chance to see how she runs. I was working on the exhaust and the pipes were so rusted I couldn't get them off, and of course I had already grinded the exhaust pipe in half so it was just a header and no down pipe. Needless to say I had to get it towed and don't have it back yet. Getting shop to do the headers while they're at it.

Also when I did it I figured out why my engine was whistling, the original gasket on the TB was completely gone so air was getting in the space b/e that and the intake manifold.
03-11-2013 02:43 PM
Gunz n tractorz
Quote:
Originally Posted by jonothehut

Sandstorm95, that totally worked. Swapped out the iac, reset the ECM, started right up with no issue. I can't believe I missed that. Thanks man.

When I do start it up it does sit around 2000rpm then slowly works its way down to around 1000rpm. Doesn't seem to be any issues though.

Sorry for the 3rd post in a row. I can't find how to edit a post.
What's the iac?
03-11-2013 02:41 PM
Gunz n tractorz
Quote:
Originally Posted by jonothehut

Hasn't been too much work. Just unbolting and bolting everything back on a couple times.
It's a tough life for us 4banger owners.
Agreed
03-11-2013 11:48 AM
jonothehut
Quote:
Originally Posted by Sandstorm95 View Post
i had the same issue but its because i didnt swap out the iac. if u compare the 4.0 one to he 2.5 there is a huge difference. The 2.5 one also says "2.5" on it to help a little
Sandstorm95, that totally worked. Swapped out the iac, reset the ECM, started right up with no issue. I can't believe I missed that. Thanks man.

When I do start it up it does sit around 2000rpm then slowly works its way down to around 1000rpm. Doesn't seem to be any issues though.

Sorry for the 3rd post in a row. I can't find how to edit a post.
03-07-2013 08:59 PM
jonothehut
Quote:
Originally Posted by Sandstorm95
i had the same issue but its because i didnt swap out the iac. if u compare the 4.0 one to he 2.5 there is a huge difference. The 2.5 one also says "2.5" on it to help a little
I think I know exactly what your talking about. I'm going to try it out this weekend.
03-07-2013 08:57 PM
jonothehut
Quote:
Originally Posted by CarolinaBound
All this work for ~1 extra HP.
Hasn't been too much work. Just unbolting and bolting everything back on a couple times.
It's a tough life for us 4banger owners.
03-03-2013 07:03 PM
Sandstorm95 i had the same issue but its because i didnt swap out the iac. if u compare the 4.0 one to he 2.5 there is a huge difference. The 2.5 one also says "2.5" on it to help a little
03-03-2013 05:47 PM
CarolinaBound All this work for ~1 extra HP.
03-03-2013 05:39 PM
jonothehut
Quote:
Originally Posted by Xpress
Remove the positive lead off the battery then ground it to the negative lead for 30 seconds. It will take a bit of time for the ECM to get to know the settings again.
I am having the same issue as Toms94YJ.
I swapped both sensors. And reset ECM and engine goes wide open. Sits around 5500 rpm. Any ideas?
06-15-2012 08:03 PM
morvayryan Never mind, I just put a paper towel in it and some painters tape, sticky side up, and bore out the hole a little and the tape caught all the shavings
06-15-2012 05:22 PM
morvayryan How did y'all bore out the hole on the intake with out getting metal shavings in it?
06-11-2012 08:13 PM
jeep30 Good info on here.
06-06-2012 08:05 AM
Toms94YJ Sorry a security torx bit.
06-05-2012 10:40 PM
morvayryan
Quote:
Originally Posted by Toms94YJ
I have a CAI on mine, originally bought it for the 2.5, the throttle body is exactly the same in the O.D. It is just bored out more internally so no fit problem. You just need to swap your sensors over from the 2.5 to the 4.0 you will need a security ROTC bit to do it though.
Sounds good, thank you!
06-05-2012 10:11 PM
Toms94YJ I have a CAI on mine, originally bought it for the 2.5, the throttle body is exactly the same in the O.D. It is just bored out more internally so no fit problem. You just need to swap your sensors over from the 2.5 to the 4.0 you will need a security ROTC bit to do it though.
06-05-2012 09:35 PM
morvayryan I'm thinking about doing this to my 2.5l but I have a question. (dont mean to thread jack...sorry) i was wondering if after the swap, do you need a new intake rather than the stock 2.5l? If I was to buy a cai do I buy one for a 2.5l or 4.0l?
03-19-2012 11:30 PM
blazerone22 So did the injectors with the throttle body help out? I;ve done the TB and have been shopping for injectors...
03-19-2012 07:43 PM
Toms94YJ Leaky injector! Problem resolved. Thanks for the help.
03-16-2012 10:30 PM
Toms94YJ Thanks. I will try it in the morning. I am also going to check the injectors and see if I have a leak. There is a strong gas smell under the hood. I appreciate the help.
03-16-2012 09:15 PM
Xpress Remove the positive lead off the battery then ground it to the negative lead for 30 seconds. It will take a bit of time for the ECM to get to know the settings again.
03-16-2012 06:14 PM
Toms94YJ How do I reset the ICM? Thanks for the help by the way.
03-16-2012 05:50 PM
Xpress Reset the ECM. Also consider doing a full tuneup. People would be amazed at how much can go wrong with these that causes these idle issues.
03-16-2012 02:48 PM
Toms94YJ Checked the vacuum lines. No leaks. I did install 19lb injectors a couple of days before. No issues. I swapped back the old throttle body. No more oil but still a very rough idle and sputtering/backfiring while driving. Do you have to adjust the timing at all with the19lb injectors. Also taking a while to start up. I have to give it some gas before she will start. Help please.
03-16-2012 01:34 PM
Xpress It helps improve acceleration, but the TB itself won't actually improve HP figures- you might see as much as 1hp gains. You really do need to open up EVERYTHING up and down river in order to see significant HP gains. With a high flow intake, a 4.0 TB, bored out intake header to match, borla exhaust headers and a custom exhaust you're going to see probably about 6-7hp in gains. It's enough to make a little difference but you need to do other stuff to see gains.
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