Lextreme II
Just call me "Lex"
- Messages
- 12,033
- Location
- City of Halos
Get a dyno tune.... I think you are still little off on the fuel/air issue.
LS400 Supercharger Project
- Thread starter ca12los
- Start date
The 1UZFE EGR Delete Kit is available for sale here.
Kinda, sorta ;-) The circuit you described is intended to shutoff the injectors when the engine is decelerating, and there is high vacuum due to the throttle being closed.
I would check to make sure you get closed contacts from the TPS when the throttle is fully closed, but also make sure they open when you come off the throttle stop. There's a procedure in nearly all Toyota FSM's to set this, and if it's not set right, the car will definitely run like cr*p.
Here's the explanation direct from Toyota:
You may have mistyped something there, because if your idle contacts are staying closed when you open the throttle, that's not correct, and the problem is inside the TPS.
The idle contacts should "open" as soon as you're off the throttle stop. "As soon as" meaning feeler gauge type distance. I don't have the specs with me, but it's only a few thousandths.
Thanks for the comments on the 1UZ; I'm being pretty careful with this motor!
stevechumo
Active Member
- Messages
- 3,054
- Location
- OC, City of Sunshine
The ECU circuit might be shorted when you changed the current to the fuel pump. But it's just a guess. You may put back the way the fuel pump harness was as before. Also if you have the TPS code, that could be the TPS itself, ECU wiring, or the the ECU itself. I'd replace the TPS first.
I don't think jumping the fuel pump will hurt anything.
It sounds to me like this is happening when the supercharger kicks in when the bypass valve closes? Under inlet vacuum the bypass on the supercharger is open as soon as you plant yourr foot it goes out of vacuum and closes the butterfly to bring on the boost.
So it sounds like the transition between boost and non boost is the issue.
You have tried 2 ecu's and 2 tps sensors and get the same thing so I don't think its either of those.
Maybe try upping the fuel pressure slightly.
Have you fitted the piggyback yet?
It sounds to me like this is happening when the supercharger kicks in when the bypass valve closes? Under inlet vacuum the bypass on the supercharger is open as soon as you plant yourr foot it goes out of vacuum and closes the butterfly to bring on the boost.
So it sounds like the transition between boost and non boost is the issue.
You have tried 2 ecu's and 2 tps sensors and get the same thing so I don't think its either of those.
Maybe try upping the fuel pressure slightly.
Have you fitted the piggyback yet?
I have connected most of the wires for the piggyback. I am just monitoring at this point. The problem is not only at boost onset it happens when cruising and the accelerator pedal is pushed slowly about 1/4 way. This is all during vacuum.
Fuel pressure shoots up to 60 - 90 PSI on boost depending on the setting of the FMU. If it was fuel related why on earth would the ECM send a TPS error??
Fuel pressure shoots up to 60 - 90 PSI on boost depending on the setting of the FMU. If it was fuel related why on earth would the ECM send a TPS error??
- Messages
- 4,790
- Location
- Houston, TX
Kinda, sorta ;-) The circuit you described is intended to shutoff the injectors when the engine is decelerating, and there is high vacuum due to the throttle being closed.
I would check to make sure you get closed contacts from the TPS when the throttle is fully closed, but also make sure they open when you come off the throttle stop. There's a procedure in nearly all Toyota FSM's to set this, and if it's not set right, the car will definitely run like cr*p.
Here's the explanation direct from Toyota:
OK I just checked everything as the manual stated. It seems the idle contacts are staying closed even when the throttle is floored. The TPS sensor tested perfectly. I have continuity through each wire from the TPS. The ECM is the only possible problem.
So how can 2 ECM's go bad????
I am going to dish out $300 for a rebuilt unit...it sucks but it should help other aspects of the car also. I opened on ECM up and I saw multiple leaky caps and a few light colored area where maybe it over heated....it also had a nasty smell to it.
So how can 2 ECM's go bad????
I am going to dish out $300 for a rebuilt unit...it sucks but it should help other aspects of the car also. I opened on ECM up and I saw multiple leaky caps and a few light colored area where maybe it over heated....it also had a nasty smell to it.
- Messages
- 4,790
- Location
- Houston, TX
You may have mistyped something there, because if your idle contacts are staying closed when you open the throttle, that's not correct, and the problem is inside the TPS.
The idle contacts should "open" as soon as you're off the throttle stop. "As soon as" meaning feeler gauge type distance. I don't have the specs with me, but it's only a few thousandths.
Thanks for the comments on the 1UZ; I'm being pretty careful with this motor!
What I meant was the ECM is not sending out a voltage of 12v to the idle circuit once the actual idle contacts do open.
Since the there is no voltage the computer thinks the TPS is closed.
The TPS is working perfect, the idle contacts open at the slightest throttle opening when tested with a miltimeter. The ECM just isn't sending out the enough voltage to the TPS sensor once the idle contact do open (0 volts when closed-12 volts when open)
This is how I understand it.... I hate to spend more $$$, but it is a must.
Since the there is no voltage the computer thinks the TPS is closed.
The TPS is working perfect, the idle contacts open at the slightest throttle opening when tested with a miltimeter. The ECM just isn't sending out the enough voltage to the TPS sensor once the idle contact do open (0 volts when closed-12 volts when open)
This is how I understand it.... I hate to spend more $$$, but it is a must.
Circuit Description
The throttle position sensor is mounted in the throttle body and detects the throttle valve opening angle. When the throttle valve is fully closed, the IDL contacts in the throttle position sensor are on, so the voltage at the terminal IDL of the engine control module become 0 V. At this time, a voltage of approximately 0.7 V is applied to the terminal VTA of the engine control module. When the throttle valve is opened, the IDL contacts go off and thus the power source voltage of approximately 12 V in the engine control module is applied to the terminal IDL of the engine control module. The voltage applied to the terminal VTA of the engine control module increases in proportion to the opening angle of the throttle valve and becomes approximately 3.2 - 4.9 V when the throttle valve is fully opened. The engine control module judges the vehicle driving conditions from these signals input from the terminals VTA and IDL, and uses them as one of the conditions for deciding the air-fuel ratio correction, power increase correction and fuel-cut control etc.
The throttle position sensor is mounted in the throttle body and detects the throttle valve opening angle. When the throttle valve is fully closed, the IDL contacts in the throttle position sensor are on, so the voltage at the terminal IDL of the engine control module become 0 V. At this time, a voltage of approximately 0.7 V is applied to the terminal VTA of the engine control module. When the throttle valve is opened, the IDL contacts go off and thus the power source voltage of approximately 12 V in the engine control module is applied to the terminal IDL of the engine control module. The voltage applied to the terminal VTA of the engine control module increases in proportion to the opening angle of the throttle valve and becomes approximately 3.2 - 4.9 V when the throttle valve is fully opened. The engine control module judges the vehicle driving conditions from these signals input from the terminals VTA and IDL, and uses them as one of the conditions for deciding the air-fuel ratio correction, power increase correction and fuel-cut control etc.
- Messages
- 4,790
- Location
- Houston, TX
I don't have the Toyota/Lexus FSM with me, but I've been looking at the overall electrical diagram (for an early LS400 1UZ), and here's what I think:
The IDL1 terminal on the ECU (32A in my schematic) should be pulled to earth via the BR wire on pin 1 and have 0 volts when the idle contacts are closed in the TB.
When the idle contacts open, then the earth is disconnected, and the IDL1 terminal gets pulled up to 12v, but not from the main ECU, but actually from the cruise control ECU via the G wire (see schematics below).
So if you're not seeing 12v at the IDL terminal when you open the throttle, have a look at your cruise control ECU.
If you'll PM me your email, I'll send you the overall electrical wiring diagram for this.
The IDL1 terminal on the ECU (32A in my schematic) should be pulled to earth via the BR wire on pin 1 and have 0 volts when the idle contacts are closed in the TB.
When the idle contacts open, then the earth is disconnected, and the IDL1 terminal gets pulled up to 12v, but not from the main ECU, but actually from the cruise control ECU via the G wire (see schematics below).
So if you're not seeing 12v at the IDL terminal when you open the throttle, have a look at your cruise control ECU.
If you'll PM me your email, I'll send you the overall electrical wiring diagram for this.
The ECM solved all my problems!!!!!
No more erratic shifting, slow acceleration (even with the blower), and check engine light is gone on hard acceleration as well.
I am led to believe that rebuilding these things should be done by a lot of us who suffer from never ending problems. Day and night difference!!!!!!
No more erratic shifting, slow acceleration (even with the blower), and check engine light is gone on hard acceleration as well.
I am led to believe that rebuilding these things should be done by a lot of us who suffer from never ending problems. Day and night difference!!!!!!
Thermactor
Member
- Messages
- 541
- Location
- San Diego
carlos, how much boost is it producing on that pulley?
Kev
New Member
- Messages
- 47
- Location
- Sydney, Australia
I guess you notice a lot more performance when driving generaly and you just put your foot down and away she goes. But will it spin the wheels off the line just by flooring it and no left foot braking.
Bet your glad its up and running at last. Well done and enjoy.
Kevin
Bet your glad its up and running at last. Well done and enjoy.
Kevin
Hey guys,
Video was to demonstrate low end torque. Even with big wheels and new tires on the back they will light up easily. On acceleration the car will take off without losing any traction.
I need to tune it ASAP. It is leaning out at about 3500 RPMs. I am sure I could hit 6 sec. 0-60 when it is tuned to about 12.0 @ WOT to redline. Maybe the regulator aint working right?? I am using the SMT6 piggyback, but I am having problems getting the car to run with it completely connected. I have many wiring diagrams, but I really do not know which one is correct. Anybody have any experience with it???
Thanks.
Video was to demonstrate low end torque. Even with big wheels and new tires on the back they will light up easily. On acceleration the car will take off without losing any traction.
I need to tune it ASAP. It is leaning out at about 3500 RPMs. I am sure I could hit 6 sec. 0-60 when it is tuned to about 12.0 @ WOT to redline. Maybe the regulator aint working right?? I am using the SMT6 piggyback, but I am having problems getting the car to run with it completely connected. I have many wiring diagrams, but I really do not know which one is correct. Anybody have any experience with it???
Thanks.
Similar threads
