MarkR Posted September 30, 2009 Share Posted September 30, 2009 I had something similar on my Corsa... yes I know it's not the same thing but the issue turned out to be the temp sensors. Something to do with the car thinking it was cold in hot weather and vice versa and getting mixed up and screwing up the idling. Quote Link to comment Share on other sites More sharing options...
carl0s Posted September 30, 2009 Author Share Posted September 30, 2009 I had something similar on my Corsa... yes I know it's not the same thing but the issue turned out to be the temp sensors. Something to do with the car thinking it was cold in hot weather and vice versa and getting mixed up and screwing up the idling. Hmm. Not the first time I've heard that. Which temp sensors would we be talking about though? Coolant temp sensor to the gauge is fine, as the needle points where it should.. the ECU has no fault codes either. Quote Link to comment Share on other sites More sharing options...
MarkR Posted September 30, 2009 Share Posted September 30, 2009 Hmm. Not the first time I've heard that. Which temp sensors would we be talking about though? Coolant temp sensor to the gauge is fine, as the needle points where it should.. the ECU has no fault codes either. I'm not sure as I didn't sort it but the ECU didn't register errors either. Quote Link to comment Share on other sites More sharing options...
carl0s Posted September 30, 2009 Author Share Posted September 30, 2009 If I piss about with the ICV - take it off, move it, put it back on, the car always works fine right after. I don't think I've ever took the ICV off, messed about, put it back on and not thought "right.. looks fine now!" (only for it to go wrong later ..) Quote Link to comment Share on other sites More sharing options...
TLicense Posted September 30, 2009 Share Posted September 30, 2009 (edited) Carlos, When the car is idling high, disconnect the TPS, you'll probably notice that as you're pulling it around it may well temporarily fix the problem, and then as you fully disconnect the TPS it will idle high again. I've seen this a couple of times, it's where the TPS plug has a slightly poor connection with the TPS sensor. It gives an intermittant signal so the ECU thinks that because the throttle butterfly is slightly open it parks the ICV solenoid. It parks at something like 60 odd % duty which is why it revs right up to over 2000 rpm. To fix this I initially tried bending the pins in the TPS sensor plug to ensure it made a good connection, but I still got a small amount of ICV parking. In the end I put a small amount of solder on the tips of the pins and that 100% solved all of my idling problems as it was then making a good connection between the TPS sensor and the loom and on to the ECU. Personally, having experienced the symptoms and seen the cause, I believe this is the problem with the vast majority of idling issues. Hope that helps. Edited September 30, 2009 by TLicense (see edit history) Quote Link to comment Share on other sites More sharing options...
carl0s Posted October 1, 2009 Author Share Posted October 1, 2009 Carlos, When the car is idling high, disconnect the TPS, you'll probably notice that as you're pulling it around it may well temporarily fix the problem, and then as you fully disconnect the TPS it will idle high again. I've seen this a couple of times, it's where the TPS plug has a slightly poor connection with the TPS sensor. It gives an intermittant signal so the ECU thinks that because the throttle butterfly is slightly open it parks the ICV solenoid. It parks at something like 60 odd % duty which is why it revs right up to over 2000 rpm. To fix this I initially tried bending the pins in the TPS sensor plug to ensure it made a good connection, but I still got a small amount of ICV parking. In the end I put a small amount of solder on the tips of the pins and that 100% solved all of my idling problems as it was then making a good connection between the TPS sensor and the loom and on to the ECU. Personally, having experienced the symptoms and seen the cause, I believe this is the problem with the vast majority of idling issues. Hope that helps. That's a good idea Tony! I'll do exactly the same with some solder. Thanks! cheers, Carl Quote Link to comment Share on other sites More sharing options...
Guest jtt97 Posted October 2, 2009 Share Posted October 2, 2009 http://www.supraforums.com/forum/showthread.php?t=450071 Here is the procedure to adjust the TPS. Read this thread. I'm assuming it is the same on Euro spec as US spec but do not quote me on that. If you just replaced it then it is probably out of adjustment. Something for you to look at. Quote Link to comment Share on other sites More sharing options...
carl0s Posted October 2, 2009 Author Share Posted October 2, 2009 http://www.supraforums.com/forum/showthread.php?t=450071 Here is the procedure to adjust the TPS. Read this thread. I'm assuming it is the same on Euro spec as US spec but do not quote me on that. If you just replaced it then it is probably out of adjustment. Something for you to look at. Thanks for the info. Having read the service manual section on how the TPS works, I'm not convinced that any of what SJ says is necessary for me though. Quote Link to comment Share on other sites More sharing options...
carl0s Posted October 6, 2009 Author Share Posted October 6, 2009 Carlos, When the car is idling high, disconnect the TPS, you'll probably notice that as you're pulling it around it may well temporarily fix the problem, and then as you fully disconnect the TPS it will idle high again. I've seen this a couple of times, it's where the TPS plug has a slightly poor connection with the TPS sensor. It gives an intermittant signal so the ECU thinks that because the throttle butterfly is slightly open it parks the ICV solenoid. It parks at something like 60 odd % duty which is why it revs right up to over 2000 rpm. To fix this I initially tried bending the pins in the TPS sensor plug to ensure it made a good connection, but I still got a small amount of ICV parking. In the end I put a small amount of solder on the tips of the pins and that 100% solved all of my idling problems as it was then making a good connection between the TPS sensor and the loom and on to the ECU. Personally, having experienced the symptoms and seen the cause, I believe this is the problem with the vast majority of idling issues. Hope that helps. I did try this Tony, and I was getting ready to thank you, and thinking to myself it was sorted (again..) when it started playing up again big time later on that day. Having re-read your post though, I didn't put solder on the 'tips' of the pins, instead I fattened-out the pins by letting them soak up some solder on both sides. I over did it initially as I couldn't get the plug to plug in, so I desoldered a bit and had quite a tight connection then, but still the same problem. Thanks for the suggestion though, it logically fits the symptoms perfectly and I was hopeful that it would fix my case too, but I guess not Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted October 7, 2009 Share Posted October 7, 2009 Damp in them can do some very odd things. Power FC's on Skylines go "berserk" if the TPS is damp internally. Quote Link to comment Share on other sites More sharing options...
TLicense Posted October 7, 2009 Share Posted October 7, 2009 I did try this Tony, and I was getting ready to thank you, and thinking to myself it was sorted (again..) when it started playing up again big time later on that day. Having re-read your post though, I didn't put solder on the 'tips' of the pins, instead I fattened-out the pins by letting them soak up some solder on both sides. I over did it initially as I couldn't get the plug to plug in, so I desoldered a bit and had quite a tight connection then, but still the same problem. Thanks for the suggestion though, it logically fits the symptoms perfectly and I was hopeful that it would fix my case too, but I guess not Sorry that's not helped. I'm sure it'll be a poor connection problem somewhere along the line though. Maybe you could read the signals at the ecu when it's running good, and then re-read them when it's having a tiz and see if one is dropping out? You should be able to just use a multi-meter to see what voltages are being generated... Quote Link to comment Share on other sites More sharing options...
Guest Luigi Posted October 10, 2009 Share Posted October 10, 2009 (edited) carl0s: I have a TT jspec which has had an idle issue for 10 months. It would cut out after the engine warmed up ...... but straight after restart it would run fine (most of the time). I used TLicense's post as a guide and went to the ICV VSV instead of the TPS. Cleaned the connector pins and twisted them slightly for positve contact. Reconnected connector and the idle issue is now no longer. Edited October 10, 2009 by Luigi (see edit history) Quote Link to comment Share on other sites More sharing options...
carl0s Posted October 10, 2009 Author Share Posted October 10, 2009 carl0s: I have a TT jspec which has had an idle issue for 10 months. It would cut out after the engine warmed up ...... but straight after restart it would run fine (most of the time). I used TLicense's post as a guide and went to the ICV VSV instead of the TPS. Cleaned the connector pins and twisted them slightly for positve contact. Reconnected connector and the idle issue is now no longer. Thanks Luigi, but I inadvertantly did do as you did. I had remembered Tony's instructions wrong, so I went and blobbed solder on all six of the ICV's pins, then realised, and did the TPS too As it happens, I fitted a known good ICV yesterday and after a few minutes of the car adjusting things (quite different to the symptoms I'd been seeing though, it was obvious that the ECU needed to pull out the ICV a bit as the car kept stalling as soon as I lifted off gas, and there was no intermittancy to it) I think it might be sorted. I'm just going to have tea now and then I'm going to go for a proper drive with a few stops along the way. Fingers crossed I was waiting to know for sure before posting though as I have a few people to thank really (whether it's fixed or not I suppose). Quote Link to comment Share on other sites More sharing options...
carl0s Posted October 10, 2009 Author Share Posted October 10, 2009 Damp in them can do some very odd things. Power FC's on Skylines go "berserk" if the TPS is damp internally. My TPS is brand new from Toyota. Hopefully the new ICV has fixed it now anyway. I'll know for sure later today. Quote Link to comment Share on other sites More sharing options...
carl0s Posted October 11, 2009 Author Share Posted October 11, 2009 (edited) I'm really at my wit's end with this After changing the ICV yesterday, I did a relatively long drive with a few stops along the way, and it looked really good. Today, I went two miles to Halfords, and upon starting the car to leave Halfords, it's playing up exactly like before. Hesitating/nearly stalling upon throttle, idling at 2,000rpm. When I first start the car, the idle starts at ~2,300, and then drops down to 1,800 - 2,000. Perhaps this is as much as the ICV can drop the idle by, if air is leaking into the engine from elsewhere? If I loosen off the TPS, then when I rotate it back and forth the idle drops momentarily, which suggests to me that the TPS is working. Can anybody think of anywhere where air could be getting into the system at idle where it shouldn't be? Or vice versa, air not getting in where it should (I notice if I allow air in through the turbo pressure sensor hoses, the idle drops). If somebody was following Tony License's Valve Stem Seal guide, what might they have done up wrong or not done up right that could cause this issue? Alternatively, is there anybody local to me who's willing to temporarily swap ICVs with me, just to know for sure that the ICV I bought is a good 'un? I'll come and do the swap - only a little job. Edited October 11, 2009 by carl0s (see edit history) Quote Link to comment Share on other sites More sharing options...
carl0s Posted October 11, 2009 Author Share Posted October 11, 2009 I'm interested in looking at the coolant temp sensor. Any ideas where this is? My dash gauge reports fine, but read a lot about people who swapped radiators and then similar problems went away .. Quote Link to comment Share on other sites More sharing options...
carl0s Posted October 11, 2009 Author Share Posted October 11, 2009 Could cam position sensor cause this ? Quote Link to comment Share on other sites More sharing options...
Steve Posted October 11, 2009 Share Posted October 11, 2009 Water temp sensor is located on the water elbow on the front left hand side of the engine. There are 2 sensors there, one with a single wire - this feeds the gauge on the dash, the other one has 2 wires - this one goes to the ECU. Quote Link to comment Share on other sites More sharing options...
carl0s Posted October 11, 2009 Author Share Posted October 11, 2009 Water temp sensor is located on the water elbow on the front left hand side of the engine. There are 2 sensors there, one with a single wire - this feeds the gauge on the dash, the other one has 2 wires - this one goes to the ECU. Thanks mate. Quote Link to comment Share on other sites More sharing options...
Steve Posted October 11, 2009 Share Posted October 11, 2009 I think i have a spare water temp sensor you can have to try if you like? Quote Link to comment Share on other sites More sharing options...
carl0s Posted October 11, 2009 Author Share Posted October 11, 2009 I think i have a spare water temp sensor you can have to try if you like? Yes please. Is it the two-wire one that goes to the ECU? I'd definitely like to try it please! Quote Link to comment Share on other sites More sharing options...
carl0s Posted October 11, 2009 Author Share Posted October 11, 2009 carl0s: I have a TT jspec which has had an idle issue for 10 months. It would cut out after the engine warmed up ...... but straight after restart it would run fine (most of the time). I used TLicense's post as a guide and went to the ICV VSV instead of the TPS. Cleaned the connector pins and twisted them slightly for positve contact. Reconnected connector and the idle issue is now no longer. Luigi.. what's the photo about? That's not the idle control valve in the picture.. ? Quote Link to comment Share on other sites More sharing options...
Steve Posted October 11, 2009 Share Posted October 11, 2009 Yes please. Is it the two-wire one that goes to the ECU? I'd definitely like to try it please! Yeah the two wire one goes to the ECU. PM me your address i will pop it in the post. Quote Link to comment Share on other sites More sharing options...
carl0s Posted October 11, 2009 Author Share Posted October 11, 2009 Yeah the two wire one goes to the ECU. PM me your address i will pop it in the post. Thanks very much! I'm getting some great help here - just wish I could get it sorted though Fingers crossed again. I'm very grateful to Phil Terminator for sending me a suspect-but-free ICV as well. I appreciate the help a lot. Quote Link to comment Share on other sites More sharing options...
carl0s Posted October 11, 2009 Author Share Posted October 11, 2009 Just off to buy a compression tester.. you never know.. Plus it might be nice to give compression numbers with the car for sale when it's finally working properly. Quote Link to comment Share on other sites More sharing options...
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