ray007 Posted December 13, 2013 Share Posted December 13, 2013 (edited) HI all, Would appreciated some help with my troubled project, nearly 2 years and counting The supra is now difficult to start up, when and if it starts the revs behave irratically, go upto 3k revs and hunting idle. the last few days i had to remove the fuel pump plug, then the car would start and play around with the plug (on and off) to get it running and most of the time keep the revs up a bit to keep it running but that dont last long before it cuts off again. The problem started about two weeks back (only been on the road about a moth), 1. initially just used to every other day cut out when slowing down to a stop or stationary but would start straight back up and run fine. 2. eventually started cutting out more often and gradually taking longer and longer to start up and smell rich 3. then occasionally when i stat the car and let it warm up it would itself cut out after about 5 mins but start back up and driver fine 4. then occasionally would have to disconnect the the fuel pump and start the car till the fuel in the system is burned off, the car would automatically rev up high abouk 2.5-3k revs and as its about to die i would plug in the fuel plug and it would run. but behave irratically, revs hunting, smoke from exhaust (smells like fuel), a few back fires/pops etc. 5. now its almost impossible to start and when does just dies after a few minutes, with above symptons. Details about my car. 1. Has had the 12v Fuel pump mod 2. is BPU, walboro fuel pump (quite new but been sitting in car for about a year), FMIC, FCD, Full DECAT. 3. New lamba, new thermostat, had new headgaskets, valve cover gaskets, camshaft seals Valve stem etc etc seals all done since i had the engine out. 4. Started off as a rolling shell, had no fuel lines with it, did install new pipes 5. had all engine vacums replaced 6. cleaned out the IACV a few months back 6.RUNNING PARALLEL TURBO as found a problem with sequential system. 7. i think coil pack are in good condition, had new coil pack clips installed 8. HAS some wiring issues, occasionally wipers come on by themselfs :-) 9. SPEEDO is temperatmental, jumps speed at times, goes from KM's at times back to MPH SPark plugs, are quite new only seen about 250 miles but have had many cold starts in garage, took these out and were carbonated. I know the plugs need changing but need to work out whats causing this. All Vacums seem ok. ANY advice would be much appreciated, if there is anyone local (london area) willing to work on it please pm me. MANY thanks in advance UPDATE: DIAGNOSTIC RESULTS: CODES 1. Code 13 G NE signal circuit 2. Code 14 ignition signal circuit 3. Code 22 Water temp sensor circuit 4. Code 78 fuel pump control circuit - could this be due to the 12v mod? This hasnt really narrowed it down for me :-) UPDATE: 07/01/2013 1. Ok first thing the timing was out due to the aftermarket cam pulleys, so reverted that back to original and re-done the timing. Result: car runs better but still cuts out when coming to a stop, revs drop low and cant seem to hold the revs 2. We then adjusted the rev speed to idle a little higher which has reduced the problem but still cuts out occasionally, usually when stopping quickly the revs drop really low and at times cant hold the rev, starts straight back up and drives fine. 3. 3. Coolant sensor - checked resistance today in the morning after not driving for a day on cold engine(on 200k setting as no reading on any other setting) i got approx 65.00??, then checked again after driving and let the engine cool down for about 6hrs its reading 35.00.. doesnt sound right?? same symptons with the sensor connected the car runs contantly near 2k revs and runs really rough - with it off take time to start on cold starts but runs fine 4. also window wipers keep giving me agro, they keep coming on themselves...usually when its not raining..arghhh any advice would be much appreciated Edited January 7, 2014 by ray007 (see edit history) Quote Link to comment Share on other sites More sharing options...
Tayfun.tugra Posted December 13, 2013 Share Posted December 13, 2013 Have you checked the wires are sturdy in the ECU? What colour smoke do you get from the exhaust when its revved? Quote Link to comment Share on other sites More sharing options...
Lee P Posted December 13, 2013 Share Posted December 13, 2013 Could be a map sensor problem or water temp sensor causing it to over fuel Check connections and then try changing sensors If you do a diagnostic it should help you Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted December 13, 2013 Share Posted December 13, 2013 Check the ECU coolant temp sensor if faulty this will cause the ECU to think its in cold start mode all the time so mixture will be permanently rich. Quote Link to comment Share on other sites More sharing options...
Ian C Posted December 13, 2013 Share Posted December 13, 2013 Those wiring problems you mention could be indicative of a bad earth as well, and that can cause all sorts of strange behaviour. Check your o2 sensor is working as well, as it sounds like it only happens when it's warm, unless you've already fouled the plugs. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 14, 2013 Share Posted December 14, 2013 Coolant temp sensor (ecu sensor, not water temp gauge sensor) could be faulty. ECU assumes 60C if it gets silly or no readings. But if it gives a resistance when cold that matches a mapped minus temp, it will add FAR too much fuel. I would also check FCD and its wiring, and pipework to the MAP sensor. Any fault codes stored? Quote Link to comment Share on other sites More sharing options...
ray007 Posted December 14, 2013 Author Share Posted December 14, 2013 Tried a new coolant temperature sensor still same problem guys Quote Link to comment Share on other sites More sharing options...
ray007 Posted December 14, 2013 Author Share Posted December 14, 2013 Weird issue.... if I disconnect the coolant temperature sensor the car starts up but struggles with the sensor connected??? Any ideas? Quote Link to comment Share on other sites More sharing options...
Pig Posted December 14, 2013 Share Posted December 14, 2013 The car will adjust the fuelling for cold start hence if the temp sensor has gone down this will cause issues. I don't know how to check it - Is nothing showing up on diagnosis? Quote Link to comment Share on other sites More sharing options...
ray007 Posted December 15, 2013 Author Share Posted December 15, 2013 The car will adjust the fuelling for cold start hence if the temp sensor has gone down this will cause issues. I don't know how to check it - Is nothing showing up on diagnosis? Tried doing a diagnostics and found out the instrument cluster for the engine management light etc isnt working its weird the car runs sweet with the sensor OFF Tried a brand new coolant temp ensor which gives problems starting the car Quote Link to comment Share on other sites More sharing options...
Tayfun.tugra Posted December 15, 2013 Share Posted December 15, 2013 (edited) not sure if you have seen this but i'll post if anyway. http://www.mkivsupra.net/vbb/showthread.php?238522-2JZ-sensor-resistance! the only reasons i can think of are: Leaking injector(s) Not that i know much about injectors... but maybe an old injector o ring gave way to the fuel pump mod? Maybe someone more experienced can confirm/deny this? Sort of makes sense...running parallel introduces little fuel until 4k revs, then it needs to inject a bath full of fuel to feed 2 hungry turbos. Open throttle - as if you had you foot on the accelerator Cold engine - and the ecu tries to heat it up by putting more fuel in it. Edited December 15, 2013 by Tayfun.tugra (see edit history) Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 15, 2013 Share Posted December 15, 2013 You must get that display working. Give the dash above a hard bang with thenpalm of your hand, It's usually bad solder joints at the connector. You can fix it yourself if you have a small soldering iron. You need to see the fault codes. Quote Link to comment Share on other sites More sharing options...
ray007 Posted December 22, 2013 Author Share Posted December 22, 2013 UPDATE: DIAGNOSTIC RESULTS CODES 1. Code 13 G NE signal circuit 2. Code 14 ignition signal circuit 3. Water temp sensor circuit 4. Code 78 fuel pump control circuit - could this be due to the 12v mod? This hasnt really narrowed it down for me :-) Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 22, 2013 Share Posted December 22, 2013 (edited) Fix # 3 first. I presume you meant to say a code 22? Either a bad water temp sensor, a bad connection to it, or a bad cables between it and the ecu / ecu connector. measure resistance of the sensor itself after a proper visual of the connector and its wires. It could be a 5V rail ground fault, check the two ground cables under the intake manifold. Hard to see, they are on two separate eyelet tags. An auto electrician familiar with electronic control unit diagnosis should be able to sort this within an hour. No need for a Supra specialist, it';s all quite basic. Once that code is gone see what you get. Edited December 22, 2013 by Chris Wilson (see edit history) Quote Link to comment Share on other sites More sharing options...
ray007 Posted December 22, 2013 Author Share Posted December 22, 2013 (edited) UPDATE: DIAGNOSTIC RESULTS CODES 1. Code 13 G NE signal circuit 2. Code 14 ignition signal circuit 3. Code 22 Water temp sensor circuit 4. Code 78 fuel pump control circuit - could this be due to the 12v mod? This hasnt really narrowed it down for me :-) Edited December 22, 2013 by ray007 (see edit history) Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted December 22, 2013 Share Posted December 22, 2013 Going by what you have said about the problem occurring when new coolant temp sensor is fitted, but starts/runs fine with the sensor disconnected, if you cannot find a fault in the wiring, I would start looking for an air leak, or the cold start air bypass valve is stuck open/failed, as if it starts/runs with the default rich mixture, then there must be more airflow present to allow this, or it would just flood/not start. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 22, 2013 Share Posted December 22, 2013 Are you sure it's the CORRECT sensor? What resistance is it showing, engine cold? Quote Link to comment Share on other sites More sharing options...
ray007 Posted January 7, 2014 Author Share Posted January 7, 2014 (edited) UPDATE: 07/01/2013 1. Ok first thing the timing was out due to the aftermarket cam pulleys, so reverted that back to original and re-done the timing. Result: car runs better but still cuts out when coming to a stop, revs drop low and cant seem to hold the revs 2. We then adjusted the rev speed to idle a little higher which has reduced the problem but still cuts out occasionally, usually when stopping quickly the revs drop really low and at times cant hold the rev, starts straight back up and drives fine. 3. Coolant sensor - checked resistance today in the morning after not driving for a day on cold engine(on 200k setting as no reading on any other setting) i got approx 65.00??, then checked again after driving and let the engine cool down for about 6hrs its reading 35.00.. doesnt sound right?? same symptons with the sensor connected the car runs contantly near 2k revs and runs really rough - with it off take time to start on cold starts but runs fine 4. also window wipers keep giving me agro, they keep coming on themselves...usually when its not raining..arghhh any advice would be much appreciated Edited January 7, 2014 by ray007 (see edit history) Quote Link to comment Share on other sites More sharing options...
ray007 Posted January 7, 2014 Author Share Posted January 7, 2014 Going by what you have said about the problem occurring when new coolant temp sensor is fitted, but starts/runs fine with the sensor disconnected, if you cannot find a fault in the wiring, I would start looking for an air leak, or the cold start air bypass valve is stuck open/failed, as if it starts/runs with the default rich mixture, then there must be more airflow present to allow this, or it would just flood/not start. sounds possible, where is the cold start air bypass valve Quote Link to comment Share on other sites More sharing options...
Bayden_uk Posted December 10, 2015 Share Posted December 10, 2015 Ecu Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted December 10, 2015 Share Posted December 10, 2015 Holy bump! ECU what? But seriously ray never did come back and tell us what was wrong? Quote Link to comment Share on other sites More sharing options...
Bayden_uk Posted December 10, 2015 Share Posted December 10, 2015 I was bored [emoji23] Quote Link to comment Share on other sites More sharing options...
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