Bayden_uk Posted May 20, 2014 Share Posted May 20, 2014 Hi all i started a thread in chat and it started to turn into a technical thread so i thought id move over here and see how it goes. i have the 2JZGE N/A so iv done a search on it and iv found a few threads on the topic but still im a little baffled by my problem. i start my cor in the morning and all is fine. i pull up at light and stop i cant even feel the engine, but as i drive her more through the day shes getting a little more rough when im stopped at lights or when idle. it was that bad one time it it put my engine light on while i was on the motorway and when i got her home it turned off the engine, let it cool down and went back an hour later, turn the key and she started fine but as soon as the revs were down it was like it was trying not to stall. now i done the diagnostic with the hair click and i got the code: 42. now the code says No.1 speed sensor signal. but would this really cause such a problem? just wondering if anyone can shed some light on this for me please. thanks in advance Ben Quote Link to comment Share on other sites More sharing options...
Scott Posted May 20, 2014 Share Posted May 20, 2014 What is it idling at? Quote Link to comment Share on other sites More sharing options...
P_Bazz Posted May 20, 2014 Share Posted May 20, 2014 Code 42 has nothing to do with it. It is probably your IACV that's a bit sticky. Here is the guide to fix it: http://www.mkivsupra.net/vbb/showthread.php?210956-How-To-Clean-Idle-Control-Valve-Cleaning-Aka-ICV-(IAC) The pictures are for a TT but it's the same for a NA. Quote Link to comment Share on other sites More sharing options...
Bayden_uk Posted May 20, 2014 Author Share Posted May 20, 2014 This is when she's idle Quote Link to comment Share on other sites More sharing options...
Bayden_uk Posted May 20, 2014 Author Share Posted May 20, 2014 Code 42 has nothing to do with it. It is probably your IACV that's a bit sticky. Here is the guide to fix it: http://www.mkivsupra.net/vbb/showthread.php?210956-How-To-Clean-Idle-Control-Valve-Cleaning-Aka-ICV-(IAC) The pictures are for a TT but it's the same for a NA. thanks bazz ill give it a look see Quote Link to comment Share on other sites More sharing options...
Scott Posted May 20, 2014 Share Posted May 20, 2014 Is it the same RPM when it's running rough? Definitely sounds like a warm idle issue which will probably be IACV related. Quote Link to comment Share on other sites More sharing options...
Graham1984 Posted May 20, 2014 Share Posted May 20, 2014 Idle rpm looks normal for when it is warm, on a cold day/start mine has had an idle of just under 2k. Quote Link to comment Share on other sites More sharing options...
Scott Posted May 20, 2014 Share Posted May 20, 2014 Idle rpm looks normal for when it is warm, on a cold day/start mine has had an idle of just under 2k. Is it -50 where you live? That sounds crazy high. I thought fast idle was 1.2-1.4k lol. Quote Link to comment Share on other sites More sharing options...
Bayden_uk Posted May 20, 2014 Author Share Posted May 20, 2014 Is it the same RPM when it's running rough? Definitely sounds like a warm idle issue which will probably be IACV related. it drops slightly when its running rough but not much at all. im off out in a minute so if it plays up again ill get a video an show you. Quote Link to comment Share on other sites More sharing options...
Bayden_uk Posted May 20, 2014 Author Share Posted May 20, 2014 i frogot to say! when i found the engine light on i pulled up an turn the engine off and then on an the engine light was off, but as soon as i picked up speed to about 50mph it was back on. since i got her home an let her cool down ive not seen the light since Quote Link to comment Share on other sites More sharing options...
Ian C Posted May 20, 2014 Share Posted May 20, 2014 Is it -50 where you live? That sounds crazy high. I thought fast idle was 1.2-1.4k lol. NA's normally have this high idle when cold from what I've heard on here i frogot to say! when i found the engine light on i pulled up an turn the engine off and then on an the engine light was off, but as soon as i picked up speed to about 50mph it was back on. since i got her home an let her cool down ive not seen the light since That's the code 42 speed sensor playing up, it only comes on if you get over a certain speed. Your engine idling badly could be a dirty O2 sensor or a sticky IACV. Try cleaning both, there are guides on here for the job if you do a search Quote Link to comment Share on other sites More sharing options...
Bayden_uk Posted May 21, 2014 Author Share Posted May 21, 2014 ok so today i managed to get a video of the poor idle. sorry the begining gets a bit dizzy. my phones strapped to my wheel. Quote Link to comment Share on other sites More sharing options...
Graham1984 Posted May 21, 2014 Share Posted May 21, 2014 Like Ian said they do have a really high cold idle sometimes, it is rare though for it to be that high. Quote Link to comment Share on other sites More sharing options...
Bayden_uk Posted May 21, 2014 Author Share Posted May 21, 2014 Like Ian said they do have a really high cold idle sometimes, it is rare though for it to be that high. If it was a high idle the engine tone would be a lot higher. The car felt like it was going to stall. I got the bits together to clean the sensors, just need to find out where they are. I'm new to working on supras. I'm used to working on landrovers Quote Link to comment Share on other sites More sharing options...
Bayden_uk Posted May 22, 2014 Author Share Posted May 22, 2014 (edited) Can anyone help me in locating the IACV and 02 sensor on my NA please. I think I found it I just want to make sure I'm right. Edited May 22, 2014 by Bayden_uk (see edit history) Quote Link to comment Share on other sites More sharing options...
P_Bazz Posted May 22, 2014 Share Posted May 22, 2014 It's on the top of the engine block, there are two sensors plugged into the the throttlebody there (the square part where the black hose connects to). The left one is the IACV. The two O2 sensors are bolted on the exhaust below the heatshield on the left side of the engine. Quote Link to comment Share on other sites More sharing options...
Bayden_uk Posted May 22, 2014 Author Share Posted May 22, 2014 Cheers bazz. I was looking in the right place then Quote Link to comment Share on other sites More sharing options...
Bayden_uk Posted May 25, 2014 Author Share Posted May 25, 2014 so i tried to get the sensor off but i cant get to the bottom screw. how can i get to it. im slowly killing it and dont want to touch it till ive had advice on how to Quote Link to comment Share on other sites More sharing options...
Bayden_uk Posted June 7, 2014 Author Share Posted June 7, 2014 finally found time to get the job done. took the idle sensor out an give it all a clean. took her for a drive an she was fine and idling normal. next day i took her for a spin an after about an hours worth of driving the problem was back. i didnt get to check the 02 sensors. the weathers been rather poo lately. how would i clean 02 sensors? i hear you cant get them wet? Quote Link to comment Share on other sites More sharing options...
Attero Posted June 7, 2014 Share Posted June 7, 2014 Have a keen interest in this thread. Often get unstable rpm at idle and at 2k when releasing throttle. The fact it happens at 2k everytime might just be a coincidence. I Reckon sensors might be the issue as I still had issues after cleaning the ICV. Quote Link to comment Share on other sites More sharing options...
P_Bazz Posted June 7, 2014 Share Posted June 7, 2014 You should be able to reach them with the heatshield off, take it real easy when undoing them the bolt heads snap very easily. It can be done with the intake pipes connected but it's a breeze when you take them off first. There are two O2 sensors, one in each part of the exhaust manifold and they're both secured with two (12mm IIRC) nuts. Pull the plugs from the engine loom and you can take them out to sit in lemon juice for a night. Best is to replace them but they are not cheap so the lemon juice trick should at least give you a clue if the problems are caused by the sensors. Quote Link to comment Share on other sites More sharing options...
Jos Posted June 8, 2014 Share Posted June 8, 2014 It could be a worn throttle body?, you could check by opening the throttle valve by hand and see if you can move the shaft in and out of the throttle body. If there is excessive play it will allow to much air in I think, had a similar problem on a supra a few months back, changed the throttle body and that fixed it. Quote Link to comment Share on other sites More sharing options...
Attero Posted June 8, 2014 Share Posted June 8, 2014 Could even be a dirty throttle body? Perhaps it needs a good clean. Quote Link to comment Share on other sites More sharing options...
mull1986 Posted June 11, 2014 Share Posted June 11, 2014 I had two o2 sensors delivered from rockauto USA for roughly £85. There's a few to choose from on there: one pin, two pins and four pins iirc. Na's have one pin. Give them a google Quote Link to comment Share on other sites More sharing options...
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