Suspect my M/T ECU needs repair? (rough start and smoke condition) [MOSTLY SOLVED]
01-15-16, 03:39 PM
#91
Ali,
At this point, other than the power steering sound it really comes down to the slow startup with lumpy idle until it corrects itself. It doesn't happen every single time but I always expect it. It does feel as if there isn't enough extra fuel being added right when the car is started. I'm still waiting on the coolant temp sensor to ship out. I am going to stop by a Toyota dealer and grab a bottle of ATF and a new funnel to have them on hand.
Again, once that lumpiness suddenly evens out the car never so much as hiccups. After startup the engine does feel more confident than before all this maintenance.
Since the car is cold right now I will film a short video of the startup. The audio should be clear enough to hear when the engine starts with rough idle and gradually clicks into normal fast idle. Hopefully the whining sound will also be audible.
If the O-ring is the issue with the PS pump-- assuming there is no damage-- should I only need to order a new one and a new folded crush washer to repair? (And of course flush the system with new ATF).
At this point, other than the power steering sound it really comes down to the slow startup with lumpy idle until it corrects itself. It doesn't happen every single time but I always expect it. It does feel as if there isn't enough extra fuel being added right when the car is started. I'm still waiting on the coolant temp sensor to ship out. I am going to stop by a Toyota dealer and grab a bottle of ATF and a new funnel to have them on hand.
Again, once that lumpiness suddenly evens out the car never so much as hiccups. After startup the engine does feel more confident than before all this maintenance.
Since the car is cold right now I will film a short video of the startup. The audio should be clear enough to hear when the engine starts with rough idle and gradually clicks into normal fast idle. Hopefully the whining sound will also be audible.
If the O-ring is the issue with the PS pump-- assuming there is no damage-- should I only need to order a new one and a new folded crush washer to repair? (And of course flush the system with new ATF).
Last edited by KahnBB6; 01-15-16 at 03:42 PM.
01-19-16, 10:54 AM
#93
When I watch that video the first thing I think of is the tps is off or not working, if ecu doesn't see the IDL pin activated on the tps during idle it does funny stuff like that. history on TPS?
check the connector for it as well if its cracked it can be loose and cause issues.
for a quick test, put the jumper in the diagnostic port to pull codes Te1 and e1, and see if the engine make a change in noise while its running, it should as when you put the jumper in the timing defaults from whatever it might be to 10. you always hear a change. if not then the tps is in the wrong position or bad as it only goes into diagnostic when its idling (it only knows its idling from the idl pin on the tps, its not that smart an ecu). if it does make a change in sound then thats probably not the issue, but worth a quick check.
check the connector for it as well if its cracked it can be loose and cause issues.
for a quick test, put the jumper in the diagnostic port to pull codes Te1 and e1, and see if the engine make a change in noise while its running, it should as when you put the jumper in the timing defaults from whatever it might be to 10. you always hear a change. if not then the tps is in the wrong position or bad as it only goes into diagnostic when its idling (it only knows its idling from the idl pin on the tps, its not that smart an ecu). if it does make a change in sound then thats probably not the issue, but worth a quick check.
01-19-16, 07:03 PM
#94
Ali,
I originally completely mixed up the TPS and IAC-V in this post. Apologies. Wasn't thinking clearly. Corrections have been emphasized.
The IAC-V connector was already deteriorated around the outside section, however it's remained snug in place despite this. Tonight I carefully replaced the plastic connector (90980-11144) wire by wire and the old one was disintegrating as I did this.
Upon starting up after replacing the connector (the engine was completely cold) the rough cold idle was there but for even less time before it corrected itself.
To my knowledge the TPS sensor has never been replaced. I ran the Te1 and e1 jumper test and I did notice a very faint change in the idle noise but it wasn't very pronounced at all.
At the same time, I pulled out my timing gun and got the distributor readjusted right on 10 BTDC.
I'll have to check the TPS. Do you know if it's the same part number for the USDM 2JZGTE TPS sensor and USDM 2JZ-GE TPS sensor? If so, I can just throw on the new OEM TT TPS sensor I have.
I originally completely mixed up the TPS and IAC-V in this post. Apologies. Wasn't thinking clearly. Corrections have been emphasized.
The IAC-V connector was already deteriorated around the outside section, however it's remained snug in place despite this. Tonight I carefully replaced the plastic connector (90980-11144) wire by wire and the old one was disintegrating as I did this.
Upon starting up after replacing the connector (the engine was completely cold) the rough cold idle was there but for even less time before it corrected itself.
To my knowledge the TPS sensor has never been replaced. I ran the Te1 and e1 jumper test and I did notice a very faint change in the idle noise but it wasn't very pronounced at all.
At the same time, I pulled out my timing gun and got the distributor readjusted right on 10 BTDC.
I'll have to check the TPS. Do you know if it's the same part number for the USDM 2JZGTE TPS sensor and USDM 2JZ-GE TPS sensor? If so, I can just throw on the new OEM TT TPS sensor I have.
Last edited by KahnBB6; 01-19-16 at 07:41 PM.
01-19-16, 08:56 PM
#95
if you heard a change in it running then it sounds like it is working. do you remember what your warm idle rpm settles at? No the main gte and main ge tps turn opposite directions, they are not interchangeable. you can use the trac tps off a gte throttle body temporarily, as that is the same as the GE main tps, but if the tps is working its best not to move it or you will have to fiddle with it to get it set right.
The other thing it sounded like it could have been was the IACV, normally the idle doesn't go up after a cold start, it would go up as high as its going to go within a couple seconds of start, yours tends to raise a little bit as it warms which is why I wonder what the fully warm idle is. if the tps was bad and ecu wasnt reading idl pin it tends to race a little bit, also iacv issues can cause it to race some cause the IACV should be lowering the idle as the engine warms. there are more possibilities but to me it sounds to be running well for the most part, so I wouldn't worry about it too much until you figure out the issue.
I can tell you when my IACV connector was cracked I thought it wouldn't affect it much as it was still seated well but it did affect things quite a bit, I have replaced that one and the tps one on my harness before. you may even need to reset the ecu after repairing that connector and see if the problem goes away or gets better again.
The other thing it sounded like it could have been was the IACV, normally the idle doesn't go up after a cold start, it would go up as high as its going to go within a couple seconds of start, yours tends to raise a little bit as it warms which is why I wonder what the fully warm idle is. if the tps was bad and ecu wasnt reading idl pin it tends to race a little bit, also iacv issues can cause it to race some cause the IACV should be lowering the idle as the engine warms. there are more possibilities but to me it sounds to be running well for the most part, so I wouldn't worry about it too much until you figure out the issue.
I can tell you when my IACV connector was cracked I thought it wouldn't affect it much as it was still seated well but it did affect things quite a bit, I have replaced that one and the tps one on my harness before. you may even need to reset the ecu after repairing that connector and see if the problem goes away or gets better again.
Last edited by Ali SC3; 01-19-16 at 09:01 PM.
01-20-16, 01:00 AM
#96
if you heard a change in it running then it sounds like it is working. do you remember what your warm idle rpm settles at? No the main gte and main ge tps turn opposite directions, they are not interchangeable. you can use the trac tps off a gte throttle body temporarily, as that is the same as the GE main tps, but if the tps is working its best not to move it or you will have to fiddle with it to get it set right.
I have not recently messed with the idle adjustment screw.
Good to know about the TT TRAC TPS sensor being the same part as the GE TPS! I also have a new one of those set aside (purchased it by accident).
The other thing it sounded like it could have been was the IACV, normally the idle doesn't go up after a cold start, it would go up as high as its going to go within a couple seconds of start, yours tends to raise a little bit as it warms which is why I wonder what the fully warm idle is. if the tps was bad and ecu wasnt reading idl pin it tends to race a little bit, also iacv issues can cause it to race some cause the IACV should be lowering the idle as the engine warms. there are more possibilities but to me it sounds to be running well for the most part, so I wouldn't worry about it too much until you figure out the issue.
I did not continue filming until the engine reached full temperature. As of now the engine always comes back down to the same stable warm idle rpm. The issue is only the rough idle at cold startup and often the engine's cold start fast idle starts up slowly rather than immediately.
I can tell you when my IACV connector was cracked I thought it wouldn't affect it much as it was still seated well but it did affect things quite a bit, I have replaced that one and the tps one on my harness before. you may even need to reset the ecu after repairing that connector and see if the problem goes away or gets better again.
I actually haven't reset the ECU yet. I'll give that a try as well.
Thanks again, Ali!
The short list now appears to be:
--reset ECU
--check IAC-V
--check TPS sensor (but probably don't touch it)
--still maybe possibly have the ECU coolant temp sensor replaced (but that's not proven to be the issue yet)
01-20-16, 10:14 AM
#97
when did you last mess with the idle air screw, did you increase it or lower it? that was my next question =)
believe it or not the warm idle should be 650, so when it was around 600 it was likely the correct base idle especially on a manual car.
another reason the idle can race like that after a start is if the idle screw is screwed in too much letting in too much extra air. this shows up as the ecu not being able to lower the idle down to 650 when warm, and tends to do odd things when cold. I would say if the tps is good then if you have played with this screw in the past, then its worth a try to mark the current position, and then bak it out one turn and try it (reset ecu again also and start car again when fully cold).
It sounds like your coolant senor is working for the most part, so hold off on that one.
so reset ecu,
check tps connector,
if that doesnt show anything try adjusting the idle screw out some, on a stock car it shouldn't be pushing the throttle open much its usually set resting against it(if you back it out enough it will just be loose, and as you tun it in you will feel when it starts pushing on the throttle blade, thats where it should be roughly resting against it but not opening it much at all). I apologize if that is a bit vague, but its how it works when you go to move it you will "feel" it.
reset the ecu after any idle air adjustment or tps adjustment.
if you have turned the screw in in the past, then that is most likely the issue. that screw needs to be pretty much backed off most of the way and then the IACV will take care of the rest.
some people do what yours is doing on purpose to raise the warm idle, and live with some popping on the cold start.
believe it or not the warm idle should be 650, so when it was around 600 it was likely the correct base idle especially on a manual car.
another reason the idle can race like that after a start is if the idle screw is screwed in too much letting in too much extra air. this shows up as the ecu not being able to lower the idle down to 650 when warm, and tends to do odd things when cold. I would say if the tps is good then if you have played with this screw in the past, then its worth a try to mark the current position, and then bak it out one turn and try it (reset ecu again also and start car again when fully cold).
It sounds like your coolant senor is working for the most part, so hold off on that one.
so reset ecu,
check tps connector,
if that doesnt show anything try adjusting the idle screw out some, on a stock car it shouldn't be pushing the throttle open much its usually set resting against it(if you back it out enough it will just be loose, and as you tun it in you will feel when it starts pushing on the throttle blade, thats where it should be roughly resting against it but not opening it much at all). I apologize if that is a bit vague, but its how it works when you go to move it you will "feel" it.
reset the ecu after any idle air adjustment or tps adjustment.
if you have turned the screw in in the past, then that is most likely the issue. that screw needs to be pretty much backed off most of the way and then the IACV will take care of the rest.
some people do what yours is doing on purpose to raise the warm idle, and live with some popping on the cold start.
01-23-16, 08:37 PM
#98
Ali, getting back to this today.
The car does appear to be running and starting better as a result of all your suggestions. It still does have some minor rough cold start idle but it doesn't last for very long at all now. It still varies in length of time but it has sometimes been no more than three seconds total now. Sometimes a bit longer but not by much.
I readjusted what I think is the idle screw. It's the one I messed with before. That is, as you suggested, just allowing the stop to rest onto it. It is no longer holding the cable throttle slightly open. Idle is now resting much closer to 650-750 rpm.
I've kept studying another diagram which suggests the idle screw is in another location but I could not get a match when comparing the printout image to my throttle body. I am 100% certain that I did not accidentally adjust the cruise control portion of the throttle-- I doubled checked and ruled that out before wrenching on anything.
This is the thread I referenced with the image of the idle adjustment screw:
https://www.clublexus.com/forums/per...set-screw.html
The TPS connector and wires appear to be fine. It's not cracked at the locking tabs or loose in any way. The TPS sensor itself I have not removed.
I did perform a battery/ECU reset.
Also, the PS fluid was not low so that was a relief, however it does look like it's about time to drain and flush it with new ATF. Still no abnormal steering behavior while operating the car.
.....
This probably rules everything out other than inspecting the IAC-V. I keep doing each bit of these tasks only in chunks due to my schedule lately.
Thanks!
The car does appear to be running and starting better as a result of all your suggestions. It still does have some minor rough cold start idle but it doesn't last for very long at all now. It still varies in length of time but it has sometimes been no more than three seconds total now. Sometimes a bit longer but not by much.
I readjusted what I think is the idle screw. It's the one I messed with before. That is, as you suggested, just allowing the stop to rest onto it. It is no longer holding the cable throttle slightly open. Idle is now resting much closer to 650-750 rpm.
I've kept studying another diagram which suggests the idle screw is in another location but I could not get a match when comparing the printout image to my throttle body. I am 100% certain that I did not accidentally adjust the cruise control portion of the throttle-- I doubled checked and ruled that out before wrenching on anything.
This is the thread I referenced with the image of the idle adjustment screw:
https://www.clublexus.com/forums/per...set-screw.html
The TPS connector and wires appear to be fine. It's not cracked at the locking tabs or loose in any way. The TPS sensor itself I have not removed.
I did perform a battery/ECU reset.
Also, the PS fluid was not low so that was a relief, however it does look like it's about time to drain and flush it with new ATF. Still no abnormal steering behavior while operating the car.
.....
This probably rules everything out other than inspecting the IAC-V. I keep doing each bit of these tasks only in chunks due to my schedule lately.
Thanks!
Last edited by KahnBB6; 01-24-16 at 01:53 AM.
02-05-16, 08:58 PM
#99
SOLVED... wait... nope, not quite. See post #102.
Part of the final issue turned out to be a bad ECU coolant temperature sensor. I replaced it today while the engine was cold and the closed loop startup was normal again! Regular idle was also MUCH smoother. I took me a moment to recall that the engine idle and transmission vibration were this smooth a couple of years back.
Idle Air Control Valve appears to be fine, though I am glad I replaced the engine harness connector for it.
I followed this thread by TheMole: https://www.clublexus.com/forums/per...-i6-sc300.html
1x 89422-20010 ECU Coolant Temp Sensor for 2JZ-GE's
1x 90430-12005 Temp Sensor Gasket (crush washer, non-reusable)
1x Single wind of teflon tape on the threads
Torque is 14ft-lbs exactly (friendly reminder to all-- DO NOT over-torque this sensor!). Uses a very deep socket 19mm bit with a long extension. I did it the fast and dirty way and lost about a gallon of coolant that I refilled but I found no air pockets afterward.
Also, in case the original sensor connector connector broke (it didn't for me) I had a spare 90980-11062 replacement connector on standby.
With this, I feel the swarm of issues are finally solved. The temp sensor probably needed replacing anyway but its failing symptoms were likely masked by the ECU, injector and worn spark plug/cap/rotor/wire issues.
The distributor is the only thing I replaced that probably wasn't at fault. Nonetheless I have a new one now.
Thanks everyone for all the help and advice!!!
Edit: I wasn't quite correct thinking I'd solved the rough cold start idle. The ECU coolant temperature sensor helped but did not ultimately cure it.
Part of the final issue turned out to be a bad ECU coolant temperature sensor. I replaced it today while the engine was cold and the closed loop startup was normal again! Regular idle was also MUCH smoother. I took me a moment to recall that the engine idle and transmission vibration were this smooth a couple of years back.
Idle Air Control Valve appears to be fine, though I am glad I replaced the engine harness connector for it.
I followed this thread by TheMole: https://www.clublexus.com/forums/per...-i6-sc300.html
1x 89422-20010 ECU Coolant Temp Sensor for 2JZ-GE's
1x 90430-12005 Temp Sensor Gasket (crush washer, non-reusable)
1x Single wind of teflon tape on the threads
Torque is 14ft-lbs exactly (friendly reminder to all-- DO NOT over-torque this sensor!). Uses a very deep socket 19mm bit with a long extension. I did it the fast and dirty way and lost about a gallon of coolant that I refilled but I found no air pockets afterward.
Also, in case the original sensor connector connector broke (it didn't for me) I had a spare 90980-11062 replacement connector on standby.
With this, I feel the swarm of issues are finally solved. The temp sensor probably needed replacing anyway but its failing symptoms were likely masked by the ECU, injector and worn spark plug/cap/rotor/wire issues.
The distributor is the only thing I replaced that probably wasn't at fault. Nonetheless I have a new one now.
Thanks everyone for all the help and advice!!!
Edit: I wasn't quite correct thinking I'd solved the rough cold start idle. The ECU coolant temperature sensor helped but did not ultimately cure it.
Last edited by KahnBB6; 02-14-16 at 06:39 PM. Reason: Grammatical corrections & update
02-14-16, 02:43 AM
#102
Apparently victory only lasts so long.
Despite having done all of these things and just replaced the ECU coolant temp sensor I am once again getting some rough cold start idle.
I'm out of ideas at this point. The inital problems at the start of this thread have been solved but not the rough cold start. Anyone?
Car has recently had installed:
-New spark plugs, plug wires, cap, rotor
-New/Reman ECU (Toyota)
-Reman OEM fuel injectors
-New OEM distributor
-New OEM ECU Coolant Temp Sensor
The only thing I have not yet done is cleaned or replaced the IACV since as far as I know the symptoms of a bad IACV are not consistent with my car's symptoms: no funny idle once past 30 seconds or less of cold startup, no dying idle at stoplights and absolutely no abnormal behavoir at any time after initial cold startup.
Could the original fuel pump or original fuel pump ECU be worth looking into?
Thanks again all. I thought this was solved :/
Despite having done all of these things and just replaced the ECU coolant temp sensor I am once again getting some rough cold start idle.
I'm out of ideas at this point. The inital problems at the start of this thread have been solved but not the rough cold start. Anyone?
Car has recently had installed:
-New spark plugs, plug wires, cap, rotor
-New/Reman ECU (Toyota)
-Reman OEM fuel injectors
-New OEM distributor
-New OEM ECU Coolant Temp Sensor
The only thing I have not yet done is cleaned or replaced the IACV since as far as I know the symptoms of a bad IACV are not consistent with my car's symptoms: no funny idle once past 30 seconds or less of cold startup, no dying idle at stoplights and absolutely no abnormal behavoir at any time after initial cold startup.
Could the original fuel pump or original fuel pump ECU be worth looking into?
Thanks again all. I thought this was solved :/
02-14-16, 09:13 AM
#103
If it makes you feel any better, you're not the only one aggravated by these cars' tendencies to revert to old behavior after a couple days of things appearing fixed. I've had that happen way too many times now to count. Someone made a comment once about there being a second ECU, but there was no follow-up... I half think it's true!
It couldn't hurt to do a temporary bypass of the fuel pump (jumper Fp and +b, I believe it is) and see if that changes anything.
It couldn't hurt to do a temporary bypass of the fuel pump (jumper Fp and +b, I believe it is) and see if that changes anything.