2JZGE Na-T TT Ecu Mod
03-26-14, 01:31 PM
#1486
Buff and Stuff get your car back they did the ignition part correct because it is running but the wired up the map and maf wrong, and that directly affects the air fuel and revving.
My guess right now is that you are getting no Maf signal at all on pin b66 and the car defaults to running off of the rpm and tps position, which means it runs horribly and super rich at all times.
the maf sensor is what the car uses to run and there was not supossed to be a change there at all.
when you move the maf sensor signal wire to 62 (pressure sensor spot), there is no longer a maf signal to the ecu which that ecu needs on PIN 66. the pressure signal to 62 is just for boost cut, twin turbo operation, and for the ecu to not display codes for it.
The maf is the more important of the 2 on the USDM and odb2 and there was no wiring change needed at all.
if they moved that wire and wired the map to 62, well that is stupid cause that is the maf signal wire and the ecu needs a maf signal wire.
The funny thing is had they not done any wiring at all and left the map sensor disconnected and just swapped maf's out it would have been fine. you wire up the map seperate in the case where your car already came with that type of maf, and yes it needs 5V for the map sensor which is not even on the wires for the 96+ maf sensor harness.
get your car back and set it back to normal and it will work, they did exactly what I said not to do.
the maf is already wired, it was not supossed to be touched at all.
I would get the maf wiring back to normal, verify the color of the maf signal wire on the connector, make it go to the maf again (check they didnt connect it to the map like for odb1), once you get all those wires back to the maf, then check down by the ecu verify that same signal color wire is in pin 66B now if they moved it to 62 you will have to move it.
MAP SENSOR GETS 3 NEW WIRES.
5V: you can splice from pin at ecu as shown on first page in post #4, or splice at tps connector. A good connection here is important.
MAP signal: Must go from map sensor to B62, you can reuse a spare wire but not the maf wire as you will need it. I say just run a new wire.
SENSOR GROUND: There is a huge difference between 12v regular grounds and 5v sensor grounds, mainly 12v ground can go anywhere to metal on the chassis. 5V sensor grounds MUST go back to the ecu for the pin for sensor grounds, as also shown in the diagram.
Essentially for odb2 SC300's, you will leave the maf connector alone and run 3 new wires. Don't touch the maf wires at all.
This is why I don't let others work on my cars, you never know what they will change and I would imagine they will think they did it right and not want to fix it.
My guess right now is that you are getting no Maf signal at all on pin b66 and the car defaults to running off of the rpm and tps position, which means it runs horribly and super rich at all times.
the maf sensor is what the car uses to run and there was not supossed to be a change there at all.
when you move the maf sensor signal wire to 62 (pressure sensor spot), there is no longer a maf signal to the ecu which that ecu needs on PIN 66. the pressure signal to 62 is just for boost cut, twin turbo operation, and for the ecu to not display codes for it.
The maf is the more important of the 2 on the USDM and odb2 and there was no wiring change needed at all.
if they moved that wire and wired the map to 62, well that is stupid cause that is the maf signal wire and the ecu needs a maf signal wire.
The funny thing is had they not done any wiring at all and left the map sensor disconnected and just swapped maf's out it would have been fine. you wire up the map seperate in the case where your car already came with that type of maf, and yes it needs 5V for the map sensor which is not even on the wires for the 96+ maf sensor harness.
get your car back and set it back to normal and it will work, they did exactly what I said not to do.
the maf is already wired, it was not supossed to be touched at all.
I would get the maf wiring back to normal, verify the color of the maf signal wire on the connector, make it go to the maf again (check they didnt connect it to the map like for odb1), once you get all those wires back to the maf, then check down by the ecu verify that same signal color wire is in pin 66B now if they moved it to 62 you will have to move it.
MAP SENSOR GETS 3 NEW WIRES.
5V: you can splice from pin at ecu as shown on first page in post #4, or splice at tps connector. A good connection here is important.
MAP signal: Must go from map sensor to B62, you can reuse a spare wire but not the maf wire as you will need it. I say just run a new wire.
SENSOR GROUND: There is a huge difference between 12v regular grounds and 5v sensor grounds, mainly 12v ground can go anywhere to metal on the chassis. 5V sensor grounds MUST go back to the ecu for the pin for sensor grounds, as also shown in the diagram.
Essentially for odb2 SC300's, you will leave the maf connector alone and run 3 new wires. Don't touch the maf wires at all.
This is why I don't let others work on my cars, you never know what they will change and I would imagine they will think they did it right and not want to fix it.
Last edited by Ali SC3; 03-26-14 at 01:38 PM.
03-26-14, 01:52 PM
#1487
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Most likely, I will have the car back to my house by Monday. I will make these changes ASAP. Any tips for removing pins? I understand that you push the pins back in with a tiny screw driver till it *clicks*, but how do you pull them out?
Thanks ALI, I really appreciate it! I will post back as soon as I make the changes.
Thanks ALI, I really appreciate it! I will post back as soon as I make the changes.
03-26-14, 08:12 PM
#1488
Lexus Test Driver
What afr is it in open loop when you have the problem, Do you have a video maybe you need to open up the throttle plate a little more. When it's warm and in closed loop what is the idle and afr then?
Could even be bad plug wires or a cracked coil connector or something like that can cause a miss. Sounds like something simple just gotta keep poking around till you find it.
Could even be bad plug wires or a cracked coil connector or something like that can cause a miss. Sounds like something simple just gotta keep poking around till you find it.
03-26-14, 08:45 PM
#1489
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I assume the "-- " means it's running super lean at that point? On my wide band, when I turn on the ignition, it will cycle up through the numbers until 20 when it reads "--"
03-26-14, 09:32 PM
#1490
Lexus Test Driver
I hope you are able to sort out your issues soon. wish i could provide some input, but i didn't do any of this mod hands-on myself. can't wait to hear how your car runs. hopefully better then mine
03-27-14, 09:30 AM
#1491
it is normal for it to go "---" full lean when you are decelerating because the engine is nor injecting fuel or igniting it when you are decelerating above a certain rpm and the tps is below a certain amount. This is called deceleration fuel cut and is very normal as it always reads lean when there is no combustion. now if you are on the gas and you see "---" then that would be an alarming issue and a good reason to let off the gas.
mylexsc400, I am almost positive you have a maf issue or an air leak in the piping somewhere or on the intake or a vac line or injector seals, or a leaky blow off valve, something to do with metered air (sometimes even leaky valve cover gaskets).
If I had to guess one of those to check first it would be the blow off valve and intake piping for any leaks, my car did the same thing when I was na-t on the stock ecu and safc, would stall unless I bring rpm's down and then let out clutch, and it was because of my large tial blow off valve that vents to atmosphere.
The pcv system must be routed correctly and see metered air from the intake pipe.
The bov cannot open under throttle modulation, if you have a Tial or a push type, you may want to get rid of it and get a SSQV or something that is a pull type which is much more sensitive to opening only under boost.
I have seen a stock TT mk4 drive like absolute crap when it lost a coupler, and if the leak is bad enough you can't even get those things to stay running after starting. This also throws off the air fuel in a major way.
When I was first na-t, I used to religiously drive my car around downshifting to 2nd then to even first sometimes not to stall it out, just like you said you have to baby it in gear till it comes down around idle and then let the clutch out if you don't want it to die out.
Don't worry about how much power it is making now, cause its not reading the air right, it will run better once its all correct.
Have someone go out and look at your bov while you are idling, particularly the piston, now blip the throttle some.
If the blow off valve opened enough to let out air on deceleration, then you have a problem.
Push type the piston goes down while accelerating and goes up/opens while decelerating.
If the piston opened enough to let air out then you need to adjust down the tension on that bov so that it does not open from regular blips of the throttle, it absolutely drives maf ecu's nuts when this happens.
On a tial you can shim the spring one washer at a time to where it will stay closed in vacuum but still opens with some boost (ask me how I know. lol).
on the greddy's or other types there is sometimes an adjustment screw on top. These types must be set properly unless you are recirculating them and then it doesn't matter as much but still has a small affect.
if you have it open to atmosphere, you pretty much want it on the stiffer side so it only opens under boost and not in vac, and this may cause flutter at lower boost levels but should still operate fine. IF you shim too much or too tight then it won't open even under boost and you need to back off some, its a fine balance on these types of BOV's.
also check your coilpack clips and wires, sometimes they don't make full contact and cause issues like that. it only takes 1 cylinder to not fire right to throw off the afr's.
mylexsc400, I am almost positive you have a maf issue or an air leak in the piping somewhere or on the intake or a vac line or injector seals, or a leaky blow off valve, something to do with metered air (sometimes even leaky valve cover gaskets).
If I had to guess one of those to check first it would be the blow off valve and intake piping for any leaks, my car did the same thing when I was na-t on the stock ecu and safc, would stall unless I bring rpm's down and then let out clutch, and it was because of my large tial blow off valve that vents to atmosphere.
The pcv system must be routed correctly and see metered air from the intake pipe.
The bov cannot open under throttle modulation, if you have a Tial or a push type, you may want to get rid of it and get a SSQV or something that is a pull type which is much more sensitive to opening only under boost.
I have seen a stock TT mk4 drive like absolute crap when it lost a coupler, and if the leak is bad enough you can't even get those things to stay running after starting. This also throws off the air fuel in a major way.
When I was first na-t, I used to religiously drive my car around downshifting to 2nd then to even first sometimes not to stall it out, just like you said you have to baby it in gear till it comes down around idle and then let the clutch out if you don't want it to die out.
Don't worry about how much power it is making now, cause its not reading the air right, it will run better once its all correct.
Have someone go out and look at your bov while you are idling, particularly the piston, now blip the throttle some.
If the blow off valve opened enough to let out air on deceleration, then you have a problem.
Push type the piston goes down while accelerating and goes up/opens while decelerating.
If the piston opened enough to let air out then you need to adjust down the tension on that bov so that it does not open from regular blips of the throttle, it absolutely drives maf ecu's nuts when this happens.
On a tial you can shim the spring one washer at a time to where it will stay closed in vacuum but still opens with some boost (ask me how I know. lol).
on the greddy's or other types there is sometimes an adjustment screw on top. These types must be set properly unless you are recirculating them and then it doesn't matter as much but still has a small affect.
if you have it open to atmosphere, you pretty much want it on the stiffer side so it only opens under boost and not in vac, and this may cause flutter at lower boost levels but should still operate fine. IF you shim too much or too tight then it won't open even under boost and you need to back off some, its a fine balance on these types of BOV's.
also check your coilpack clips and wires, sometimes they don't make full contact and cause issues like that. it only takes 1 cylinder to not fire right to throw off the afr's.
Last edited by Ali SC3; 03-27-14 at 09:53 AM.
03-27-14, 10:17 AM
#1492
I am not sure why it didn't occur to me before but if you wanted to run the TT ecu mod with the stock distributor, then all you would need is an IGF simulator or faker circuit. People have made them but are not really that sharing with the info online, but there are places to buy them. I am going to look into the circuit and post it up for those that want to try it. then you wont have to touch any of the ignition except install the IGF simulator, and the injectors etc..
03-27-14, 10:25 AM
#1493
Lexus Test Driver
Thank you for that info Ali. I will be re-checking my BOV this week. It is recirculated, so idk if that makes a difference or not. Also, all the piping seems to be perfect, and my mechanic swears that the coilpacks are all good too. Also, what is the best way to check if the MAF is working properly?
03-27-14, 11:06 AM
#1494
it does make a difference to recirculate it but recirculating is not perfect there is a delay but it generally keeps you from stalling out cause the air gets there eventually. you want to minimize the amount of air going through this recirculating path to just boost air more or less.
I think the maf is a resistance check, you can also try cleaning it since its a hotwire type.
maybe you got too large of injectors since -20 percent fuel trim makes me think there is a big problem somewhere. did they leave the noise filter next to the stock coilpack, it should be left there and plugged in, its a white looking small plug with 2 wires on it by the stock coil. if you remove this all sorts of wierd things happen, I never mentioned not to remove it but didn't think anyone would really do that so double check.
I think the maf is a resistance check, you can also try cleaning it since its a hotwire type.
maybe you got too large of injectors since -20 percent fuel trim makes me think there is a big problem somewhere. did they leave the noise filter next to the stock coilpack, it should be left there and plugged in, its a white looking small plug with 2 wires on it by the stock coil. if you remove this all sorts of wierd things happen, I never mentioned not to remove it but didn't think anyone would really do that so double check.
03-27-14, 12:00 PM
#1495
Lexus Test Driver
it does make a difference to recirculate it but recirculating is not perfect there is a delay but it generally keeps you from stalling out cause the air gets there eventually. you want to minimize the amount of air going through this recirculating path to just boost air more or less.
I think the maf is a resistance check, you can also try cleaning it since its a hotwire type.
maybe you got too large of injectors since -20 percent fuel trim makes me think there is a big problem somewhere. did they leave the noise filter next to the stock coilpack, it should be left there and plugged in, its a white looking small plug with 2 wires on it by the stock coil. if you remove this all sorts of wierd things happen, I never mentioned not to remove it but didn't think anyone would really do that so double check.
I think the maf is a resistance check, you can also try cleaning it since its a hotwire type.
maybe you got too large of injectors since -20 percent fuel trim makes me think there is a big problem somewhere. did they leave the noise filter next to the stock coilpack, it should be left there and plugged in, its a white looking small plug with 2 wires on it by the stock coil. if you remove this all sorts of wierd things happen, I never mentioned not to remove it but didn't think anyone would really do that so double check.
However, the bad news is that both my upper and lower oil pans are leaking really bad. This is going to be costly to repair...
Last edited by myLEXsc400; 03-27-14 at 12:04 PM. Reason: forgot info about BOV
03-27-14, 12:33 PM
#1496
I am not sure why it didn't occur to me before but if you wanted to run the TT ecu mod with the stock distributor, then all you would need is an IGF simulator or faker circuit. People have made them but are not really that sharing with the info online, but there are places to buy them. I am going to look into the circuit and post it up for those that want to try it. then you wont have to touch any of the ignition except install the IGF simulator, and the injectors etc..
03-27-14, 03:05 PM
#1499
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Alright, so I took my car to another shop and they did a leakdown test, and it turns out my have a leaky injector #1, because its leaking from the seals. The tech says that that should be my only issue. Also my boost gauge would read -15 not the -20 that it should in vaccum. I really hope that this is the case, and not anything else. Basically it is an installation error. Apparently the BOV is working perfectly.
However, the bad news is that both my upper and lower oil pans are leaking really bad. This is going to be costly to repair...
03-27-14, 05:57 PM
#1500
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How hard are you guys pushing to get the pin into the connector. I am afraid I am going to break it. It goes nearly all the way in but when you look at the face of the plug, the pin still needs to come in another 1 or 2 mm
Edit* Nevermind, the pins the shop had left in the car that I was trying to use were the wrong type. I stole pins out of my PnP harness from the AEM FIC I was gonna use.
Edit* Nevermind, the pins the shop had left in the car that I was trying to use were the wrong type. I stole pins out of my PnP harness from the AEM FIC I was gonna use.
Last edited by BuffNStuff; 03-27-14 at 10:20 PM.