Sc300 stalls immediatly AEM v1 NA-t
06-12-15, 05:37 PM
#1
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Sc300 stalls immediatly AEM v1 NA-t
I just had my car dyno tuned yesterday. (379whp/389wtq on 10psi on 91oct)
On the drive home, the car died in traffic. I sat there for a good 2 minutes with people honking, and it finally started back up, and I limped it home. Today I go to start the car, and it wont stay running at all. It will start and then die instantly unless I keep giving it gas and keep the revs up.
I pulled the IACV off and checked it. I checked resistance of all pins and theyre perfect, the pigtail has power at all pins except 2 and I can see the plunger thing move when I turn the key to "on".
With the IACV removed from the engine, I can start the car and it will run but at like 3k rpm.
I checked fuel pressure and it is at 42psi with key on engine off. I did the 12v fuel mod after installing the big 450lph walbro that's in the tank. Before doing the mod, it did the same thing where it wouldn't stay running because of the fuel pump ecu.
I talked to my tuner and he said he was having trouble getting it to idle correctly, but it ran great when he was tuning it and when I was test driving it. Something happened on the drive home, and I can't figure it out. PLEASE HELP!
All mods are in sig. I am also running is300 coils.
On the drive home, the car died in traffic. I sat there for a good 2 minutes with people honking, and it finally started back up, and I limped it home. Today I go to start the car, and it wont stay running at all. It will start and then die instantly unless I keep giving it gas and keep the revs up.
I pulled the IACV off and checked it. I checked resistance of all pins and theyre perfect, the pigtail has power at all pins except 2 and I can see the plunger thing move when I turn the key to "on".
With the IACV removed from the engine, I can start the car and it will run but at like 3k rpm.
I checked fuel pressure and it is at 42psi with key on engine off. I did the 12v fuel mod after installing the big 450lph walbro that's in the tank. Before doing the mod, it did the same thing where it wouldn't stay running because of the fuel pump ecu.
I talked to my tuner and he said he was having trouble getting it to idle correctly, but it ran great when he was tuning it and when I was test driving it. Something happened on the drive home, and I can't figure it out. PLEASE HELP!
All mods are in sig. I am also running is300 coils.
06-15-15, 12:37 PM
#6
moved to performance section.
if the IACV is installed, can you get it to start by stepping on the gas a hair?
idle page was not setup/tuned properly.
hook up the laptop and increase your idle % numbers, its probably set too low so the engines not getting enough air after starting.
There is a "park value on that page which is basically what the ecu puts the IACV in for engine starting.
since your engine is starting its telling me your IACV is actually working, when it stalls right away it tells me the idle map is not setup properly.
so after its started the ecu looks up the chart at the top of the idle page with all the rpm's and idle percentages.
increase the idle percentages for the rpm's you idle in after the start down to where you idle when warm (so from 600-1600ish give or take).
there is also a positive and negative learn values under the advanced idle page, set those to more to allow more range of automatic adjustment.
now when you start it, it should catch an idle.
if the IACV is installed, can you get it to start by stepping on the gas a hair?
idle page was not setup/tuned properly.
hook up the laptop and increase your idle % numbers, its probably set too low so the engines not getting enough air after starting.
There is a "park value on that page which is basically what the ecu puts the IACV in for engine starting.
since your engine is starting its telling me your IACV is actually working, when it stalls right away it tells me the idle map is not setup properly.
so after its started the ecu looks up the chart at the top of the idle page with all the rpm's and idle percentages.
increase the idle percentages for the rpm's you idle in after the start down to where you idle when warm (so from 600-1600ish give or take).
there is also a positive and negative learn values under the advanced idle page, set those to more to allow more range of automatic adjustment.
now when you start it, it should catch an idle.
Last edited by Ali SC3; 06-15-15 at 12:43 PM.
06-15-15, 12:50 PM
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Sc300 stalls immediatly AEM v1 NA-t
well the strange part is that it ran great while my tuner had it on the dyno. I even test drove it before I took it home and it ran like a champ. On the drive home something changed and thats what lead to all my problems. Is it possible the idle part of the tune changed? My negative battery cable was loose so Idk if maybe that can play a part in it because im pretty sure it was loose while he was tuning it.
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06-16-15, 10:18 AM
#8
since we are talking about an aem ems, if it didn't change, then I would be surprised. not saying its your problem, but on a standalone its usually something in the settings especially since it does run when you remove the valve giving it alot of air.
the range of adjustment is tunable, so it really depends on what the tuner and what range of adjustment was set, and electrical problems can make it hard for the tuner to set it up right as it can change the percent values enough when the problem is fixed to not be in the set range of adjustment anymore.
like normally they set the idle a little high and set the correction to lower the idle, but the correction often is not set tu raise the idle much cause it causes hunting of idle, and you are going on the assumption that the original value was set high and the correction would lower it. if you had some sort of issue where it was not set high enough in the first place, and the settings wont allow it to raise the idle only lower it, you get to the point where you start it and it just stalls, so that is what I thought could be going on, but I haven't seen your basemap or the car running so its hard to say, but at least you have something to look at now.
welcome to the world of standalones. often you will need another retune for small stuff in winter if you did it in summer, not the main fuel map or timing map but oftern the small trims and idle adjustments.
injector crank pulse can affect how the car starts in winter, as in summer it will usually start no problem even if its off so that is another one that may have to revisit in winter. most tuners have a good idea what common setup values are and enter those as a rough idea, but its impossible to know what each car will like for each season.
my first tune I had a o2 sensor wire that was shorting out somewhere and it threw alot of things off. make sure the electrical is 100% before your next retune or after you correct the issue, you will have to correct the tune again.
I would also make sure the tuner corrected all the issues in the 1101 base map if you are on vvti coils and they used the 1101 basemap. if they used the 1100 gte basemap then it should be fine.
mainly the ignition phasing values should have been corrected and the crank sync should be set to falling edge and timing resynched. most tuners know this by now but its not a bad idea to ask cause if the ignition phasing is not corrected it can blow the motor on coilpacks.
the range of adjustment is tunable, so it really depends on what the tuner and what range of adjustment was set, and electrical problems can make it hard for the tuner to set it up right as it can change the percent values enough when the problem is fixed to not be in the set range of adjustment anymore.
like normally they set the idle a little high and set the correction to lower the idle, but the correction often is not set tu raise the idle much cause it causes hunting of idle, and you are going on the assumption that the original value was set high and the correction would lower it. if you had some sort of issue where it was not set high enough in the first place, and the settings wont allow it to raise the idle only lower it, you get to the point where you start it and it just stalls, so that is what I thought could be going on, but I haven't seen your basemap or the car running so its hard to say, but at least you have something to look at now.
welcome to the world of standalones. often you will need another retune for small stuff in winter if you did it in summer, not the main fuel map or timing map but oftern the small trims and idle adjustments.
injector crank pulse can affect how the car starts in winter, as in summer it will usually start no problem even if its off so that is another one that may have to revisit in winter. most tuners have a good idea what common setup values are and enter those as a rough idea, but its impossible to know what each car will like for each season.
my first tune I had a o2 sensor wire that was shorting out somewhere and it threw alot of things off. make sure the electrical is 100% before your next retune or after you correct the issue, you will have to correct the tune again.
I would also make sure the tuner corrected all the issues in the 1101 base map if you are on vvti coils and they used the 1101 basemap. if they used the 1100 gte basemap then it should be fine.
mainly the ignition phasing values should have been corrected and the crank sync should be set to falling edge and timing resynched. most tuners know this by now but its not a bad idea to ask cause if the ignition phasing is not corrected it can blow the motor on coilpacks.
06-17-15, 11:28 AM
#9
Man I don't miss my AEM V2!
Wish I could help you more but there are way to many variables or potential problem areas to address. My only advise is take it to a professional tuner that is proficient in AEM. Someone that tunes 2JZ cars on AEM often will be able to point to the issue right away.
Wish I could help you more but there are way to many variables or potential problem areas to address. My only advise is take it to a professional tuner that is proficient in AEM. Someone that tunes 2JZ cars on AEM often will be able to point to the issue right away.
06-17-15, 12:46 PM
#10
Its not uncommon to have to get a retune done the tuner can only get to so many things in one dyno session and its most important to dial in the main fuel and timing map cause that is where you push the car the hardest, sometimes the settings for idle etc.. aren't tweaked as optimally as you are used to the stock ecu doing.
I have driven my car actually for several months with no idle valve, you can also just press on the throttle some while you are starting it and give it a little throttle to keep it idling. after a minute or so it should be able to hold an idle on itself as a warm engine idles with higher rpm on the same amount of air.
If you want me to look over your basemap I can take a look and possibly make a couple changes to get the idle correction working better if that is the problem. just pm me.
I have driven my car actually for several months with no idle valve, you can also just press on the throttle some while you are starting it and give it a little throttle to keep it idling. after a minute or so it should be able to hold an idle on itself as a warm engine idles with higher rpm on the same amount of air.
If you want me to look over your basemap I can take a look and possibly make a couple changes to get the idle correction working better if that is the problem. just pm me.
06-18-15, 10:23 PM
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Sc300 stalls immediatly AEM v1 NA-t
I dont have any AEM software or anything on my computer. Tune was done by a professional at a shop. He tunes cars that compete in the Pirelli World Challenge, and he seems pretty proficient.
I put a new battery in it because it wouldnt start back up very well and I was told by my tuner that the AEM is very sensitive to voltage differences so I just replaced the battery. It does now start up after it stalls.
But it still does stall if the rpms go below 1000rpm. This happens frequently when I am coming up to a red light and have to push in the clutch and press the brakes. I can sometimes catch it before it stalls if manually ease the rpms down to where it wants to idle.
My tuner seems to believe its not the tune because it wasnt happening to him when he was tuning it. Kinda seems like hes annoyed if I even hint that it might be something wrong with the tune. Idk..
I had planned to take the car to Cali this weekend and hit some canyons with a few friends but I obviously dont trust it to go anywhere.
Any chance this could be a TPS issue? When I did the tt ecu mod way back when...I had messed with the idle screw and the TPS. I mentioned that to the tuner and he said I never should have touched the Idle screw but that its unlikely that its my problem.
I put a new battery in it because it wouldnt start back up very well and I was told by my tuner that the AEM is very sensitive to voltage differences so I just replaced the battery. It does now start up after it stalls.
But it still does stall if the rpms go below 1000rpm. This happens frequently when I am coming up to a red light and have to push in the clutch and press the brakes. I can sometimes catch it before it stalls if manually ease the rpms down to where it wants to idle.
My tuner seems to believe its not the tune because it wasnt happening to him when he was tuning it. Kinda seems like hes annoyed if I even hint that it might be something wrong with the tune. Idk..
I had planned to take the car to Cali this weekend and hit some canyons with a few friends but I obviously dont trust it to go anywhere.
Any chance this could be a TPS issue? When I did the tt ecu mod way back when...I had messed with the idle screw and the TPS. I mentioned that to the tuner and he said I never should have touched the Idle screw but that its unlikely that its my problem.
06-18-15, 11:24 PM
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Sc300 stalls immediatly AEM v1 NA-t
What if I raised my idle using the set screw? Would that help to give me a bigger buffer for it to catch the falling rpms? or would it throw everything off? I know I would need to readjust the tps if I move the set screw.
06-19-15, 04:03 PM
#14
the aem doesn't care that much about where you have the tps set or the idle set screw as long as you do the tps setup in the software after any changes, so its not from something you did before your tune.
do you have a wideband on the car when driving around? what does it show before it stalls, does it show lean or rich.
sometimes if the settings arent right it wont go lean like its supossed to and the rich mixture will make it stall.
most times its just the idle settings.
you could raise the idle set screw some and it could help if its a idle problem, but it will throw off the idle settings some and you would need to have it set up right for that, for now you should be able to do a few turns without it being too bad and it will probably help the stalling. it can affect other things like starting also. its something you usually do on the fly but If you get the software on a laptop I can tell you the basics and getting the idle isn't that bad. that is basically what alot of tuners say but if you look at it you can see how much went into it or not. Ill pm you my address.
do you have a wideband on the car when driving around? what does it show before it stalls, does it show lean or rich.
sometimes if the settings arent right it wont go lean like its supossed to and the rich mixture will make it stall.
most times its just the idle settings.
you could raise the idle set screw some and it could help if its a idle problem, but it will throw off the idle settings some and you would need to have it set up right for that, for now you should be able to do a few turns without it being too bad and it will probably help the stalling. it can affect other things like starting also. its something you usually do on the fly but If you get the software on a laptop I can tell you the basics and getting the idle isn't that bad. that is basically what alot of tuners say but if you look at it you can see how much went into it or not. Ill pm you my address.
Last edited by Ali SC3; 06-19-15 at 04:06 PM.
07-14-15, 10:18 PM
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Sc300 stalls immediatly AEM v1 NA-t
Okay well, I dont have the AEM v1 tune file yet because it is still at the shop. I decided to switch to a V2 in hope that the V1 was bad. (I also wanted flex fuel so it wasnt just a waste) Even with the v2 and a retune, I have the same issue. The shop tech and the tuner are going to play with the idle set screw and the tps and get it back to factory spec, after that they are going to data log and try to catch what happens when it stalls on my tuners computer.
Would the fact that I have a GE with a supra v2 box cause this? Any wiring differences that I am not aware of between using a supra tt box and the tt ecu mod?
It's literally like the ignition has been cut if the rpms fall below 1000. No chance of catching the rpms with hitting the gas pedal. You cant catch it. It just straight dies. Can removing all the VSVs cause this? I removed all the VSVs and all the egr stuff including the vacuum tank.
Can a short in one of the sensors cause this? I still have to reroute the wheel well harness and my temp gauge flickers back and fourth sometimes between working and not working.
This is the first point since I started this project car 3 years ago that I have felt like giving up and selling it because I never get to drive it without some impossible weird symptom that doesnt allow the car to run properly. Lol Google has been no help either along with supraforums. I cant find another thread where someone had the exact same problem.
Would the fact that I have a GE with a supra v2 box cause this? Any wiring differences that I am not aware of between using a supra tt box and the tt ecu mod?
It's literally like the ignition has been cut if the rpms fall below 1000. No chance of catching the rpms with hitting the gas pedal. You cant catch it. It just straight dies. Can removing all the VSVs cause this? I removed all the VSVs and all the egr stuff including the vacuum tank.
Can a short in one of the sensors cause this? I still have to reroute the wheel well harness and my temp gauge flickers back and fourth sometimes between working and not working.
This is the first point since I started this project car 3 years ago that I have felt like giving up and selling it because I never get to drive it without some impossible weird symptom that doesnt allow the car to run properly. Lol Google has been no help either along with supraforums. I cant find another thread where someone had the exact same problem.