Black_Supra Posted June 19, 2011 Share Posted June 19, 2011 Hey guys, when i start my MKIV it idles at around 600 RPM, pretty nice but after a few minutes when the engine warm up it idles at 1000 - 1200 RPM, that to much, what could it be? Idlingsensor ? Quote Link to comment Share on other sites More sharing options...
Black_Supra Posted June 19, 2011 Author Share Posted June 19, 2011 Addition: When i turn on the heater system i get no warm air, just read a little bit here in forum, it can stick together with the idle, right ? Quote Link to comment Share on other sites More sharing options...
marc_p Posted June 20, 2011 Share Posted June 20, 2011 Could be a multitude of problems. Does the car ever overheat or head high on the temps? Quote Link to comment Share on other sites More sharing options...
Attero Posted June 20, 2011 Share Posted June 20, 2011 I have the same problem. Just thought it was the ICV. Quote Link to comment Share on other sites More sharing options...
Black_Supra Posted June 20, 2011 Author Share Posted June 20, 2011 Watertemp is at 95 C at normal-fast driving ... read out the diagnostic system and the control light showed me NO failures ... Quote Link to comment Share on other sites More sharing options...
Black_Supra Posted June 21, 2011 Author Share Posted June 21, 2011 I have the same problem. Just thought it was the ICV. You solved the Problem ? Wat it the ICV ? Quote Link to comment Share on other sites More sharing options...
marc_p Posted June 21, 2011 Share Posted June 21, 2011 You solved the Problem ? Wat it the ICV ? Idle Control Valve It could be that but I'd be more concerned about the heating, when you turn the temperature control, can you hear the motor working behind the dash? Quote Link to comment Share on other sites More sharing options...
Black_Supra Posted June 22, 2011 Author Share Posted June 22, 2011 Idle Control Valve It could be that but I'd be more concerned about the heating, when you turn the temperature control, can you hear the motor working behind the dash? Yes, the motor is working, i can hear it ... Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted June 22, 2011 Share Posted June 22, 2011 (edited) Could be a wiring issue, could be the ICV is gummed up internally, could be an air leak on the engine side of the TB, could be the throttle pot is worn, damaged or needs resetting. Any decent garage should be able to sort it out, the system is the same on the Supra as 98% of fairly modern petrol engines. Edited June 22, 2011 by Chris Wilson Making position of possible air leak clearer. (see edit history) Quote Link to comment Share on other sites More sharing options...
EMPEROR Posted June 22, 2011 Share Posted June 22, 2011 Yeah, sounds like an air leak before the TB to me, but still lots of other things could be the issue... Quote Link to comment Share on other sites More sharing options...
Black_Supra Posted June 23, 2011 Author Share Posted June 23, 2011 (edited) Hey guys, i cleaned the ICV, it was very manky ... just drive around a while after this and the engine idled on 700 RPM ... a few hours (maybe 5 or 6 hours) later it idled again around 1100 (the whole time, no cold-start)... sometimes when i start the engines it idles directly at 600/700 RPM ... but ofter it idles 1000/1100/1200 too ... could this all stick together with the air temperature/moisture etc ?? Edited June 23, 2011 by Black_Supra (see edit history) Quote Link to comment Share on other sites More sharing options...
jmcc42uk Posted June 23, 2011 Share Posted June 23, 2011 I'm having exactly the same problem. Any ideas on what to try next mate? Resetting the ECU? Quote Link to comment Share on other sites More sharing options...
dwayne Posted June 23, 2011 Share Posted June 23, 2011 i've been having the same issues for around a year now and i have tried all the methods mentioned here. this weekend i'll be looking at air leaks and any bad earthing issues so i'll let you know if i get anywhere this time. Quote Link to comment Share on other sites More sharing options...
Ian C Posted June 23, 2011 Share Posted June 23, 2011 If your ICV was manky, try cleaning the throttle body butterfly and stuff as well, it could be that it's not quite closing properly and so letting in more air than it should be. You can test by pushing it closed via the cable cam while it's idling high. Probably best to be parked up at this point, not at traffic lights Quote Link to comment Share on other sites More sharing options...
Black_Supra Posted June 25, 2011 Author Share Posted June 25, 2011 let me know dwayne what it could be ... @ Ian C: Could it be no temp sensor ? I think about it cause i get no warm air and the idling is different and i think the difference stick together with the temperatures ... Quote Link to comment Share on other sites More sharing options...
dwayne Posted June 25, 2011 Share Posted June 25, 2011 well i cleaned every sensor and the butterfly, checked wiring and still not fixed it. i did find 2 small leaks in the manifold where a vacuum hose and somekind of aftermarket sensor was fitted so i sealed those. sometimes my idle bounces in rythm slightly at certain revs (around 15-1600) so i started the car without the TPS connected and it did the exact same thing only it was worse so i am sure its down to that for me. i'll be getting an expert to come round now to confirm and hopefully fix it cos it is now out of my league unfortunately but if it isnt that and he finds another problem i'll let you know Quote Link to comment Share on other sites More sharing options...
Black_Supra Posted June 26, 2011 Author Share Posted June 26, 2011 sounds bad dwayne you got too a superior/above-averange fuel consumption while driving ? Quote Link to comment Share on other sites More sharing options...
dwayne Posted June 26, 2011 Share Posted June 26, 2011 i would say so but i have 1000cc injectors and HKS fcon V pro ecu which hasnt been remapped for about 3 years so i think thats not helping on fuel consumption Quote Link to comment Share on other sites More sharing options...
Black_Supra Posted June 27, 2011 Author Share Posted June 27, 2011 oh okay, my setup is just BPU... i watched the last days: cold, rainy, moisture - 1000-1200 RPM dry, warm - 700 RPM Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted June 27, 2011 Share Posted June 27, 2011 oh okay, my setup is just BPU... i watched the last days: cold, rainy, moisture - 1000-1200 RPM dry, warm - 700 RPM The engine maybe not getting hot enough to come fully out of the warm up part of the maps. Have you tried a brand new, genuine thermostat? If it is running cool it will give lousy MPG and may well fast idle at times. Quote Link to comment Share on other sites More sharing options...
Black_Supra Posted June 27, 2011 Author Share Posted June 27, 2011 (edited) this could be possible. The whole system gets no warm air through the air condition because the thermostate dont open ... right ? Edited June 27, 2011 by Black_Supra (see edit history) Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted June 27, 2011 Share Posted June 27, 2011 It may be because the thermostat is not CLOSING properly to allow a rapid warm up, then it should cycle between open / shut to maintain design running temp. If it didn't open the coolant would boil. The stat is under the cover that forms part of the stub the bottom rad hose goes to on the engine. It's a bit of a pain to remove. Quote Link to comment Share on other sites More sharing options...
Black_Supra Posted June 27, 2011 Author Share Posted June 27, 2011 thank you very much Chris .... i will replace the thermostate, further i resetted the ecu and i cleaned the ICV, next point would be checking for air leaks right ? Quote Link to comment Share on other sites More sharing options...
Black_Supra Posted July 2, 2011 Author Share Posted July 2, 2011 Dont know what to do ... just replaced the thermostat today, when i start the engine it idles fine at 700 RPM but after a few minutes idling rises up to constant 1350 RPM... Quote Link to comment Share on other sites More sharing options...
dwayne Posted July 2, 2011 Share Posted July 2, 2011 i copied this from somewhere a while back so you could try this now (assuming you cleaned the TB already) TPS Adjustment Procedure and Testing Procedure - This is the Throttle Position Sensor Adjustment Procedure. What you will need: 1. Multimeter or Ohm Meter 2. Screw Driver (Philips) 3. .65mm (.026 inch) Feeler Gauge 4. Other size feeler gauges listed below to verify tests. Procedure: 1. Loosen the two screws holding the sensor on just enough so it can be turned. The Adjustment is very precise so just loosen the screw enough to turn the sensor. 2. Insert feeler gauge between the throttle stop screw and the stop lever. 3. Connect one tester probe to terminal IDL and the other to terminal EL2. When looking at the TPS as it sits they are the two left connectors. Since we are simply checking for resistance it does not matter which probe end goes to which terminal. 4. Very slowly turn the sensor clockwise until the ohm meter deflects to 0 ohms (no continuity) and then retighten both screws. 5. Recheck continuity between the terminals. a. Insert a .54mm (.021 inch) feeler gauge between stop screw and stop level. You should see continuity. b. Insert a .70mm (.028 inch) feeler gauge between stop screw and stop level. You should see no continuity. Remember you are making tiny adjustments so it is very diificult to set the sensor in the correct place. You will probably need a few attempts to get it correct. Feeler Gauges are simply little pieces of metal that are precise thicknesses. All the ones needed are common in a set and you can get the set at sears are most tool stores. They are also very cheap. EDIT: I was adjusting a TPS today and realized there was an important trick I left out of my procedure. After you have adjusted the TPS and have the correct resistance, you have to be very careful when tightening the screws that hold then sensor to the throttle body. I generally turn one 1/8 of a turn and then the other 1/8 of a turn and repeat going back and forth until the screws are tight. This will keep the TPS from moving and changing the setting ..... if you were just to tighten one and then the next and will throw off your adjustment and you will have to do it again...basically you want to tighten the screws as evenly as possible. Testing Procedure for eletrical specifications: This is the procedure to make sure your TPS is fully adjusted and in working condition. What you will need: 1. Ohm meter or multimeter 2. .016 inch and .019 inch feeler gauge Procedure: 1. Make note of which terminal is which for future reference. When looking at the top of the TPS we will can Terminal 1 the very left terminal and Terminal 4 the far right terminal. Terminals 2 and 3 are inbetween. 2. With throttle body closed: Connect ohm meter to terminal 1 and 3. Resistance will be between .34k and 6.30k ohms. 3. With .016 inch feeler gauge between stop screw and stop lever, measure resistance between terminal 1 and 2. Resistance should read under .5k ohms. 4. With .019 inch feeler gauge between stop screw and stop lever, measure resistance between terminal 1 and 2. Resistance should read under infinite aka open circuit. 5. With throttle body opened completely, connect terminal 1 and 3...resistance should read 2.4 - 11.2k ohms. 6. With throttle body opened completely, connect terminal 1 and 4...resistance should read 3.1 - 7.2k ohms. Quote Link to comment Share on other sites More sharing options...
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