james750 Posted April 22, 2008 Share Posted April 22, 2008 ok, so when i first start up my mj the throttle revs up super high and stays there until li shut it off, restart it, and press on the gas. Is this TPS, CPS?? Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted April 22, 2008 Share Posted April 22, 2008 Not TPS. Probably IAC. Edit: Your throttle cable could be sticking somewhere. Link to comment Share on other sites More sharing options...
james750 Posted April 23, 2008 Author Share Posted April 23, 2008 IAC? ill check to see if it is sticking... Link to comment Share on other sites More sharing options...
BLHTAZ Posted April 23, 2008 Share Posted April 23, 2008 IAC = Idle Air Control motor. It should be on the front of the throttle body beside the TPS (left of when looking from front). Link to comment Share on other sites More sharing options...
james750 Posted April 23, 2008 Author Share Posted April 23, 2008 cool that fixed it thanx! Link to comment Share on other sites More sharing options...
fiatslug87 Posted April 23, 2008 Share Posted April 23, 2008 cool that fixed it thanx! Did you just clean it or replace it? Link to comment Share on other sites More sharing options...
james750 Posted April 24, 2008 Author Share Posted April 24, 2008 cool that fixed it thanx! Did you just clean it or replace it? I tried cleaning it, that didnt work, so i replaced it. :D Link to comment Share on other sites More sharing options...
luke87 Posted April 24, 2008 Share Posted April 24, 2008 how much did that run you.? the cheapest i got mine for was $83.00. and it wasnt called the IAC in the parts store computer. it was something different.. now.. if i could only remember the name.....:( Link to comment Share on other sites More sharing options...
BLHTAZ Posted April 24, 2008 Share Posted April 24, 2008 AIS Solenoid is the more common modern day name for it now. Maybe that was it...?? Link to comment Share on other sites More sharing options...
james750 Posted April 24, 2008 Author Share Posted April 24, 2008 For me it was listed in the computer as an IAC valve at all 3 auto stores i went to. Carquest: $120, Napa:"Dealer Part Only" , Checker $60 :D and in stock! Link to comment Share on other sites More sharing options...
carnuck Posted April 26, 2008 Share Posted April 26, 2008 The NAPA store you went to didn't have someone qualified behind the counter if they told you dealer only! I work for NAPA in Bellevue, WA and specialize in Jeeps, AMCs and other "unusual" vehicles. I think I need to start a post with "need NAPA part numbers?" Link to comment Share on other sites More sharing options...
james750 Posted April 26, 2008 Author Share Posted April 26, 2008 The NAPA store you went to didn't have someone qualified behind the counter if they told you dealer only! I work for NAPA in Bellevue, WA and specialize in Jeeps, AMCs and other "unusual" vehicles. I think I need to start a post with "need NAPA part numbers?" I think the guy just told me that b/c he didnt even know what the part was, he typed things in on the computer for nearly 5 minutes asking if i had a manual or auto, type of engine, type of front axle (not sure what this has to do with finding the right iac), etc. and then told me it was a dealer part. Link to comment Share on other sites More sharing options...
james750 Posted May 1, 2008 Author Share Posted May 1, 2008 bringing it back, uggghhh!!! :headpop: So its been running fine since last update, until TODAY. I went to Denver to put the topper back on and it had the same problem where it would rev up high for about 10 secs, then calm down, came back to conifer, and the problem went away again. Is it related to temp(much hotter in DEN today) altitude (5000 Denver 8800 Conifer)? what it does when i consider it running normal is starts and goes to around 1500 rpms for a split second after start and then goes back to normal idle, bu t i know that our other xjs don't do that, so it may not be normal. Could it also be a defective new IAC? don't think it is a vac leak because it calms back down after a few seconds. Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted May 1, 2008 Share Posted May 1, 2008 Is it related to temp(much hotter in DEN today) altitude (5000 Denver 8800 Conifer)? Your MAT sensor controls air/fuel mix according to intake manifold temp. Your MAP sensor controls " " according to barometric pressure. You can try changing them. But I would see if it continues to do it at the temp and altitude you usually reside at. If it does I'd change out the IAC again (might be faulty) and have you cleaned out the whole throttle body area out already? Link to comment Share on other sites More sharing options...
maddzz1 Posted May 1, 2008 Share Posted May 1, 2008 If it runs fine until hot you may also want to test your oxygen sensor. The engine runs on a preset until it reaches a certain temp and then starts getting info from the oxygen sensor. Link to comment Share on other sites More sharing options...
james750 Posted May 1, 2008 Author Share Posted May 1, 2008 well, last night it did it once in conifer. Idk if the oxygen sensor, It only does it on initial startup. and oxygen sensor would cause idle problems whenever at a full clutched stop, right? Ill try picking up a MAP sensor tommorow. if it doesnt improve, ill change IAC, then oxygen i guess. Link to comment Share on other sites More sharing options...
james750 Posted May 1, 2008 Author Share Posted May 1, 2008 could it be the idle speed stepper motor? on initial startup it revs high and goes back down and doesnt rev up high anymore. Link to comment Share on other sites More sharing options...
maddzz1 Posted May 1, 2008 Share Posted May 1, 2008 If it does it on start up i don't think it would be the oxygen sensor as the comp isnt using it yet. i must have misread something in your post as i thought it was happening after the truck warmed up. Speed stepper motor and iac are the same thing i believe. Link to comment Share on other sites More sharing options...
james750 Posted May 1, 2008 Author Share Posted May 1, 2008 If it does it on start up i don't think it would be the oxygen sensor as the comp isnt using it yet. i must have misread something in your post as i thought it was happening after the truck warmed up. Speed stepper motor and iac are the same thing i believe. It did do it after warm for a while until after i replaced IAC, then it stopped for a while, and now it does it on initial startup, then stops until I start it up again. yeah, i didnt know what the speed stepper motor was to tell u the truth, it was just a recommendation that i found on wikianswers for someone with a similar problem. Link to comment Share on other sites More sharing options...
135Boom Posted May 1, 2008 Share Posted May 1, 2008 I am in the exact same boat at you are. I have cleaned the IAC, replaced the EGR cause it wasnt doing so well, replaced the TPS, replaced the oxygen sensor, cleaned the TB....... It is intermittent (doesnt do it all the time) and in fact didnt do it for about a week, and now its back. SO, its not a vacuum leak. What I did find last night was a broken Coolant Temperature Sensor, so I am replacing that. Otherwise, I don't know what to do. I am purchasing a new IAC to see if that will do the trick too. Besides the MAT and MAP, I don't know if I have any sensors to replace, haha. Link to comment Share on other sites More sharing options...
james750 Posted May 2, 2008 Author Share Posted May 2, 2008 sounds EXACTLY LIKE MY PROBLEM, btw, on that wikianswers, there was mention of CTS causing the problem too. Link to comment Share on other sites More sharing options...
maddzz1 Posted May 2, 2008 Share Posted May 2, 2008 If you read about the coolant temp sensor on this page it could cause these problems. http://www.lunghd.com/Tech_Articles/Eng ... ostics.htm Link to comment Share on other sites More sharing options...
135Boom Posted May 2, 2008 Share Posted May 2, 2008 my bad....what was broken on my truck was the little knock sensor right above the oil pan, but on the block drivers side. The CTS is above that and behind a bracket (pain in the @$$ to get to). SO, I just havent had a knock sensor. MY TRUCK IS FIXED THOUGH!!!!!!! :) I bought a new IAC and it fixed the problem for me. My old one didnt move freely, infact it didnt move at all, haha. Any idea what the sensor is on the PAX side of the tranny, 2 wire. If you take it out it has a little ball bearing on the end? Link to comment Share on other sites More sharing options...
135Boom Posted May 2, 2008 Share Posted May 2, 2008 sounds EXACTLY LIKE MY PROBLEM, btw, on that wikianswers, there was mention of CTS causing the problem too. .........SO, I would replace your IAC for sure. I cleaned the piss out of my old one and it wasnt enough. ALSO, make sure you have your EGR silenoid lines correctly routed. Mine were crossed. They are the tiny little vacuum lines underneath your airtube. To find out, go to the drivers side of the engine compartment and there is a little white deal with two orange wires going to it. Behind that there is a vacuum line coming into an electrical egr silenoid...there should be vacuum on the incoming line (electric connector side/ front of vehicle) and no vaccum on the two port exit. Mine was backwards....which will cause improper EGR action from the sounds of it. The high idle deal is the IAC most likely though. REPLACE IT. :) Link to comment Share on other sites More sharing options...
james750 Posted May 2, 2008 Author Share Posted May 2, 2008 I already replaced the IAC. I'm going to run up to chker and pick up a new MAP, MAT, and CTS and see if replacing those fixes it, I'm a little desperate to get it running b/c of a trail run i am going on Sunday. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now