2JZGE Na-T TT Ecu Mod
02-12-15, 03:59 AM
#2416
The jumper always works when you set the tps properly, I did check to confirm it changed into that noise changing mode. And the idle does stay high when fully warmed up.
I don't think I'll be starting the car this weekend as it's going to be to cold.
I don't think I'll be starting the car this weekend as it's going to be to cold.
02-12-15, 10:43 AM
#2417
the idle should come down when fully warmed up if the iacv is working and the few screws we have talked about that can affect the idle are in the right position (lower position, higher positions let in more air and IACV cannot subtract air that the throttle blade lets through).
a proper working setup should let you hear the sound when you do the timing jumper.
it shouldn't shoot much past 2k rpm's when first starting.
it should settle around 1100-1400rpm's when cold.
when warm it should decrease to 650-800 rpms, usually a little before o2 feedback kicks in (watch wideband).
a proper working setup should let you hear the sound when you do the timing jumper.
it shouldn't shoot much past 2k rpm's when first starting.
it should settle around 1100-1400rpm's when cold.
when warm it should decrease to 650-800 rpms, usually a little before o2 feedback kicks in (watch wideband).
02-12-15, 02:20 PM
#2418
the idle should come down when fully warmed up if the iacv is working and the few screws we have talked about that can affect the idle are in the right position (lower position, higher positions let in more air and IACV cannot subtract air that the throttle blade lets through).
a proper working setup should let you hear the sound when you do the timing jumper.
it shouldn't shoot much past 2k rpm's when first starting.
it should settle around 1100-1400rpm's when cold.
when warm it should decrease to 650-800 rpms, usually a little before o2 feedback kicks in (watch wideband).
a proper working setup should let you hear the sound when you do the timing jumper.
it shouldn't shoot much past 2k rpm's when first starting.
it should settle around 1100-1400rpm's when cold.
when warm it should decrease to 650-800 rpms, usually a little before o2 feedback kicks in (watch wideband).
02-12-15, 02:36 PM
#2419
one of your idle screws is still way too open, that is the only way to have an 1100rpm idle with an iacv. either that or the IACV is bad but if it goes from 2k to 1100 I think the iacv is working and its at its lowest position at that point and the rest is just extra air from the idle screws the ecu has no control over. idling at 1100rpm is not going to make the ecu happy, I would correct this first and then worry about the misfires if they are still there.
02-12-15, 03:08 PM
#2420
Its kind of weird because the higher the %tp at idle the less the throttle gets cracked. Meaning that when I correct the tps back all the way to one side(lowest %tp) I will actually be cracking the throttle more with the idle air screw.
Maybe there is some middle ground here?
Maybe there is some middle ground here?
02-17-15, 10:28 AM
#2421
I read that several times and I have no idea what you mean.
there are 2 parts to this, first you set the throttle blade position via the screws, then you set the tps.
it will not make sense to do it any other way, and right now your throttle blade is opened too much if the idle wont come down to 800 or so ever.
the idle screw physically moves the shaft.
The butterfly moves with the shaft, and the tps prongs move with the shaft.
The tps can be moved in the slot, but that only changes the reading, and not where the shaft is.
right now your shaft is open and letting in too much air.
shut the shaft some by turning in the idle screws (The regular one needs to be backed out, and one under throttle cable bracket from the picture needs to be screwed in more)
then you can use the tps slot to get the tps back into the right % number.
If you are turning the screws the right way to close the throttle body and lower the idle, the tps % will lower also. if its increasing then there is a problem cause I don't see how that can happen.
there are 2 parts to this, first you set the throttle blade position via the screws, then you set the tps.
it will not make sense to do it any other way, and right now your throttle blade is opened too much if the idle wont come down to 800 or so ever.
the idle screw physically moves the shaft.
The butterfly moves with the shaft, and the tps prongs move with the shaft.
The tps can be moved in the slot, but that only changes the reading, and not where the shaft is.
right now your shaft is open and letting in too much air.
shut the shaft some by turning in the idle screws (The regular one needs to be backed out, and one under throttle cable bracket from the picture needs to be screwed in more)
then you can use the tps slot to get the tps back into the right % number.
If you are turning the screws the right way to close the throttle body and lower the idle, the tps % will lower also. if its increasing then there is a problem cause I don't see how that can happen.
02-17-15, 02:12 PM
#2422
Isn't it a joy trying to talk about throttle bodies over the internet haha.
I think I got where the confusion came in. How are you setting the idle air screw before the tps? I've been doing it the other way around based on the manual.
The idle was at 1000 with the actual plate cracked as little as possible (at the idle air screw). This was at about 11% tp. If I rotate the tps max counter clockwise I can get about 8.5%, but here I have to turn the idle air screw further opening the throttle plate. The screw goes in while monitoring the tps for that 0 to infinity change with the feeler gauges as stated in the manual.
I'm 99% sure the screw next to the cruise one is in a far as it could go because of how its designed.
I think I got where the confusion came in. How are you setting the idle air screw before the tps? I've been doing it the other way around based on the manual.
The idle was at 1000 with the actual plate cracked as little as possible (at the idle air screw). This was at about 11% tp. If I rotate the tps max counter clockwise I can get about 8.5%, but here I have to turn the idle air screw further opening the throttle plate. The screw goes in while monitoring the tps for that 0 to infinity change with the feeler gauges as stated in the manual.
I'm 99% sure the screw next to the cruise one is in a far as it could go because of how its designed.
02-18-15, 09:43 AM
#2423
Yes I think we are narrowing down an issue to the tps. the tps is the very last thing you adjust despite what the manual may say, sometimes its not so straight forward and can get out of order (not often) but the individual procedures should be right.
'when you mention the part that you had it down to 8.5% and 1100rpm, but then you had to turn in the screw more per the manual? you should have just turned the tps to achieve that o to infinity change at the right spot, not the idle screw. maybe the manual says that but I have never done it that way and I have done quite a few of them that run correctly. sounds like you almost had it right. the actual tps % does not matter, the ecu reads it when it starts so it knows wheteher its 4 or 7 or 8 or whatever, it just needs to know when the idl comes on and off.
ok so the one next to the cruise is in as far as it can go, check.. we are good here.
the idle screw on top should be mostly backed out, when its mostly backed out it does not crack the throttle open it just sits there. if you screw it in a few turns from there it will touch and then open the throttle plate. you need to back it off to where its not touching it for now.
then adjust the tps in the slots to achieve the desired o to infinity on the IDL.
do not readjust the idl screw unless you are trying to raise the rpm.
'when you mention the part that you had it down to 8.5% and 1100rpm, but then you had to turn in the screw more per the manual? you should have just turned the tps to achieve that o to infinity change at the right spot, not the idle screw. maybe the manual says that but I have never done it that way and I have done quite a few of them that run correctly. sounds like you almost had it right. the actual tps % does not matter, the ecu reads it when it starts so it knows wheteher its 4 or 7 or 8 or whatever, it just needs to know when the idl comes on and off.
ok so the one next to the cruise is in as far as it can go, check.. we are good here.
the idle screw on top should be mostly backed out, when its mostly backed out it does not crack the throttle open it just sits there. if you screw it in a few turns from there it will touch and then open the throttle plate. you need to back it off to where its not touching it for now.
then adjust the tps in the slots to achieve the desired o to infinity on the IDL.
do not readjust the idl screw unless you are trying to raise the rpm.
02-18-15, 02:59 PM
#2425
let us know how it goes. hopefully once it starts to warm up you should see it try and idle down to 650-800. resetting the ecu after the adjustment and before starting might be a good idea so it will relearn the iacv position. you can wait for it to relearn without resetting but it might be confusing that way to the ecu.
I usually start there and then turn the screw in like a 1/4 turn or so till it just barely raises the idl and park it but you don't have to do that. I think the whole problem was I suggested this as a cure to the stalling when coming out of gear issue, but the real fix apparently was to do a maf delete so undo this and look into map conversion.
most everyone with a single turbo and US gte ecu gets a vpc/safc or map ecu you just sort of have to it looks like. its not that much of a price to pay for a turbo ecu that may ultimately pass emissions.
basically the reason why I use the JDM ecu is to avoid all the maf stuff, but that only works on obd1 easily since there is nothing to plug in to tell.
I usually start there and then turn the screw in like a 1/4 turn or so till it just barely raises the idl and park it but you don't have to do that. I think the whole problem was I suggested this as a cure to the stalling when coming out of gear issue, but the real fix apparently was to do a maf delete so undo this and look into map conversion.
most everyone with a single turbo and US gte ecu gets a vpc/safc or map ecu you just sort of have to it looks like. its not that much of a price to pay for a turbo ecu that may ultimately pass emissions.
basically the reason why I use the JDM ecu is to avoid all the maf stuff, but that only works on obd1 easily since there is nothing to plug in to tell.
02-18-15, 04:46 PM
#2426
let us know how it goes. hopefully once it starts to warm up you should see it try and idle down to 650-800. resetting the ecu after the adjustment and before starting might be a good idea so it will relearn the iacv position. you can wait for it to relearn without resetting but it might be confusing that way to the ecu.
I usually start there and then turn the screw in like a 1/4 turn or so till it just barely raises the idl and park it but you don't have to do that. I think the whole problem was I suggested this as a cure to the stalling when coming out of gear issue, but the real fix apparently was to do a maf delete so undo this and look into map conversion.
most everyone with a single turbo and US gte ecu gets a vpc/safc or map ecu you just sort of have to it looks like. its not that much of a price to pay for a turbo ecu that may ultimately pass emissions.
basically the reason why I use the JDM ecu is to avoid all the maf stuff, but that only works on obd1 easily since there is nothing to plug in to tell.
I usually start there and then turn the screw in like a 1/4 turn or so till it just barely raises the idl and park it but you don't have to do that. I think the whole problem was I suggested this as a cure to the stalling when coming out of gear issue, but the real fix apparently was to do a maf delete so undo this and look into map conversion.
most everyone with a single turbo and US gte ecu gets a vpc/safc or map ecu you just sort of have to it looks like. its not that much of a price to pay for a turbo ecu that may ultimately pass emissions.
basically the reason why I use the JDM ecu is to avoid all the maf stuff, but that only works on obd1 easily since there is nothing to plug in to tell.
02-19-15, 09:46 AM
#2427
you are obd2 right? the problem is though is that even if everything is checking out you still might not be able to drive the car with the maf and not pick up misfire codes. If gte owners have to convert to map when they slap a big single on there to avoid misfires, then you probably have to also. I'm not sure if its required but I did post those threads a while back where people posted similar issues and said that the conversion to map fixes them. its gotta be that or a distributor issue I am thinking, or on a long shot a bad injector.
you are thinking about it wrong you can't just focus on the codes to get them to go away for a little bit, wont happen like that. on obd2 if its not all jiving then its going to throw those codes. you can get lucky maybe or run some e85, might help, might hurt, but really if the ecu is injecting the wrong amount of fuel and timing (due to maf reading assuming twin turbo's that flow a lot more off idle than a single turbo), then its going to misfire, and the only way to correct it is to make the ecu think its in a load where it does inject the right fuel and timing, and people do that with a safc/vpc or a map ecu.
converting to a jdm ecu would probably solve the drivability problems and codes, but it wont plug in or work as an obd2 system at all.
I myself am looking to do the usdm ecu with a map ecu in the future to get the advantage of larger baseline injectors to start with and avoid the maf issues, hopefully it works as well as the jdm ecu.
I have read mk4 gte's can make 6-700hp on stock ecu's with the vpc/safc combo so maybe thats a vital part of the link is map conversion when going single turbo.
Its probably not what you want to hear, but I don't get to choose the solutions I just experiment/reason and figure them out.
you are thinking about it wrong you can't just focus on the codes to get them to go away for a little bit, wont happen like that. on obd2 if its not all jiving then its going to throw those codes. you can get lucky maybe or run some e85, might help, might hurt, but really if the ecu is injecting the wrong amount of fuel and timing (due to maf reading assuming twin turbo's that flow a lot more off idle than a single turbo), then its going to misfire, and the only way to correct it is to make the ecu think its in a load where it does inject the right fuel and timing, and people do that with a safc/vpc or a map ecu.
converting to a jdm ecu would probably solve the drivability problems and codes, but it wont plug in or work as an obd2 system at all.
I myself am looking to do the usdm ecu with a map ecu in the future to get the advantage of larger baseline injectors to start with and avoid the maf issues, hopefully it works as well as the jdm ecu.
I have read mk4 gte's can make 6-700hp on stock ecu's with the vpc/safc combo so maybe thats a vital part of the link is map conversion when going single turbo.
Its probably not what you want to hear, but I don't get to choose the solutions I just experiment/reason and figure them out.
Last edited by Ali SC3; 02-19-15 at 09:52 AM.
02-19-15, 11:56 AM
#2429
most people use a vpc/safc combo with the US ecu when going single turbo.
is it required to make a single turbo run right on the usdm ecu? probably is from what I read, but I can't tell you guys for sure remember I don't even have an obd2 car or a usdm ecu I am just trying to help out.
Buff's was working better for some reason but I thought he did have the same stalling issue getting out of gear which is normal due to single turbo + maf.
sounds like all he needed was a map conversion to be prefect at that point.
187 seems to have additional misfires like mylexsc400 has, in addition to the stalling issue (which is being masked by a high idle right now).
I think 187 needs to get that idle down again which I had wrongly suggested we rais to try and cure the stalling issue (this was incorrect).
the propoer solution was the conversion to map to help with those issues, not raising the idl which confuses the ecu and I Think causes the misfires.
hopefully fixing the idle will help with the misfires. then, if it does, to cure the stalling issue correctly you would need to convert to map sensor.
does any of this make sense? I am really thinking about putting a giant JDM ecu only label on the first page.
never had to work so hard to make a maf delete sound like a good idea.
the benefits of being able to pass emissions on a factory turbo ecu should outweigh the pain you might have to go through to install and setup a piggyback for 96-97 years.
IF it doesn't well then you should just use the jdm ecu or a standalone at this point cause I am not sure I can be of much more help unless you guys want me to keep on guessing, but its hard for me to keep guessing at things when I already think the problem is the maf (for the stalling not the misfires).
Wish it was as easy as 92-95 but its not like its difficult to install a piggyback, I installed the map ecu and fired it up in like an hour and a half the first time.
you can even pay a little more and find a vpc/safc combo with a fields harness for a US mk4 supra and that will be more or less plug and play.
is it required to make a single turbo run right on the usdm ecu? probably is from what I read, but I can't tell you guys for sure remember I don't even have an obd2 car or a usdm ecu I am just trying to help out.
Buff's was working better for some reason but I thought he did have the same stalling issue getting out of gear which is normal due to single turbo + maf.
sounds like all he needed was a map conversion to be prefect at that point.
187 seems to have additional misfires like mylexsc400 has, in addition to the stalling issue (which is being masked by a high idle right now).
I think 187 needs to get that idle down again which I had wrongly suggested we rais to try and cure the stalling issue (this was incorrect).
the propoer solution was the conversion to map to help with those issues, not raising the idl which confuses the ecu and I Think causes the misfires.
hopefully fixing the idle will help with the misfires. then, if it does, to cure the stalling issue correctly you would need to convert to map sensor.
does any of this make sense? I am really thinking about putting a giant JDM ecu only label on the first page.
never had to work so hard to make a maf delete sound like a good idea.
the benefits of being able to pass emissions on a factory turbo ecu should outweigh the pain you might have to go through to install and setup a piggyback for 96-97 years.
IF it doesn't well then you should just use the jdm ecu or a standalone at this point cause I am not sure I can be of much more help unless you guys want me to keep on guessing, but its hard for me to keep guessing at things when I already think the problem is the maf (for the stalling not the misfires).
Wish it was as easy as 92-95 but its not like its difficult to install a piggyback, I installed the map ecu and fired it up in like an hour and a half the first time.
you can even pay a little more and find a vpc/safc combo with a fields harness for a US mk4 supra and that will be more or less plug and play.
Last edited by Ali SC3; 02-19-15 at 12:07 PM.
02-19-15, 12:30 PM
#2430
I can feel your frustration Ali_Sc3 and I'm right there with you...I'm just going to ditch the USDM ecu and go JDM. Ditch the MAF and pick up an IAT, and ditch 550cc's and get some 440's (unless a JDM ecu can handle 550cc's WITHOUT a piggyback.) Looks like I have some hunting to do!
I will never need to pass emissions here where I live so this is not a problem for me at all.
I will never need to pass emissions here where I live so this is not a problem for me at all.