LS 430: Hitting the gas pedal does not accelerate the car ( Time Delay )
08-26-10, 08:32 AM
#16
No. The sticky carbon collects on the flap and in the TB where the flap sits when closed. The flap is also hinged at 3 and 9 o'clock, so it only contacts the TB when it's closed. I've had it stick shut on my old Toyota 4runner, especially just after engine startup (carbon was stickier when cold, I guess). I'd depress the accelerator...no response. Depress more. Nothing. More, then the TB flap would break free and fuel would flow into the TB. FYI, my toyota truck had a cabled accelerator, so no flap sensors to throw codes. The cable goes from the gas pedal to a spring on the side of the TB. When you depress the accelerator, it pulls the cable, which opens the TB flap and more fuel/air flow into the TB. With modern vehicles, it's the same, except the accelerator has a sensor that senses how much it's depressed. It sends the signal to a motor on the side of the TB, which opens the flap. Same principles, just more complicated and failure prone, IMHO (why would toyota change? to save $$?)
Disconnect the big pipe that goes from the airbox to the TB. You can now see the TB flap. Don't spray carb cleaner straight into the flap. With the engine off, you can gently push in the flap (it's hinged), spray some carb cleaner on a stainless toothbrush, and gently scrub the inside of the TB where it touches the flap. Be careful as the TB flap sensor is at 12 o'clock (at least on my LX), so I don't scrub that part. I then spray carb cleaner on a clean rag and wipe up the residue. Reintall the plumbing to the TB and you're good to go.
According to a Toyota mechanic who used to maintain my truck (started his own shop), you should do this every 30K miles. I did it on my wife's LX at 60K mi (first time) and there was some buildup. I repeated it at 90K mi and there was only a tiny bit of buildup. My old toyota truck had 120K mi before it was done.
Disconnect the big pipe that goes from the airbox to the TB. You can now see the TB flap. Don't spray carb cleaner straight into the flap. With the engine off, you can gently push in the flap (it's hinged), spray some carb cleaner on a stainless toothbrush, and gently scrub the inside of the TB where it touches the flap. Be careful as the TB flap sensor is at 12 o'clock (at least on my LX), so I don't scrub that part. I then spray carb cleaner on a clean rag and wipe up the residue. Reintall the plumbing to the TB and you're good to go.
According to a Toyota mechanic who used to maintain my truck (started his own shop), you should do this every 30K miles. I did it on my wife's LX at 60K mi (first time) and there was some buildup. I repeated it at 90K mi and there was only a tiny bit of buildup. My old toyota truck had 120K mi before it was done.
08-26-10, 08:37 AM
#17
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Couldnt get in touch with my friend. I called him several times but no response.
I aslo did some research on the Flap Throttle body heres a very good thread:
https://www.clublexus.com/forums/ls4...-cleaning.html
What a write up
I wish he had piuctures of the whole process
I aslo did some research on the Flap Throttle body heres a very good thread:
https://www.clublexus.com/forums/ls4...-cleaning.html
What a write up
I wish he had piuctures of the whole process
08-26-10, 08:41 PM
#20
With my 4runner, definitely yes....flap didn't stick to the TB housing, meaning the accelerator accelerated the car immediately when I depressed it. With the LX, no difference, as it wasn't sticking, and there wasn't significant build-up after 60K mi.
08-26-10, 08:45 PM
#21
Every car has the same issue. I think it's more dependent on mileage...more miles, more air & fuel pass through the TB=more buildup. My 4runner was 14 yrs old and had about 125K mi on it when it was sticking. Mechanic said I should clean the TB every 30K mi, regardless of the make of car. If the buildup is really bad, one can remove the TB and soak it in carb cleaner for the older model cars, but not the new ones like the LS w/ the sensor inside. Just clean it every 30K mi (~2.5 yrs) or so and it should be fine...just add it to the list of preventative maintenance.
08-27-10, 07:30 AM
#22
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yeah that too ^ ^ ^ 
well you all know what i'm gonna say. the cheapest and 'sometimes' easiest fix which is what i do first and then if it doesn't help i look at all those other things, is to just reset it. unhook the negative battery terminal for 30 minutes than connect it back up. if it helps it was pretty much free, if not, well it was free and was worth a shot. makes my car faster for a couple weeks anyways. i notice when i drive like an old guy for a couple weeks straight that my car tends to accelerate like an old guy after a while too.
well you all know what i'm gonna say. the cheapest and 'sometimes' easiest fix which is what i do first and then if it doesn't help i look at all those other things, is to just reset it. unhook the negative battery terminal for 30 minutes than connect it back up. if it helps it was pretty much free, if not, well it was free and was worth a shot. makes my car faster for a couple weeks anyways. i notice when i drive like an old guy for a couple weeks straight that my car tends to accelerate like an old guy after a while too.
exactlly what I go thru
, I always drive like and old dude (save on MPG's )
08-27-10, 05:08 PM
#23
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My friends says He cleaned the Throttle Body but still no use ,,
His next shot is going to be TB Sensor Cleaning
Any Other suggestions ???
His next shot is going to be TB Sensor Cleaning
Any Other suggestions ???
Last edited by uae; 08-27-10 at 05:13 PM.
08-29-10, 07:42 PM
#24
Sounds to me like it could be a fuel delivery issue. Your friend should replace the fuel filter and check fuel pressures at the fuel rail. If the filter is good and pressures are low, it could also be a fuel pump on its way out. I'd also recommend checking for codes with an OBDII scanner as well as monitoring sensor values while driving the vehicle for anything out of whack. Sometimes a bad sensor can wreak havoc with the new engine control systems.
How many miles on the car?
Andrew
How many miles on the car?
Andrew
03-16-11, 01:46 PM
#25
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I have a 2004 LS430, it runs fine since I purchased it new until recently. The incident is when I drive on the road, suddenly it looses power, the engine is still running, the accelerater stops functioning, I have to pull the car to the road side and turn off the engine, after I restart the engine, it runs normal again. The mileage is 56,000 miles. It only happened sometimes. I took the car to a dealer, the mechanics can not repeat the problem, and can not diagnosis the problem from the computer either. The mechanics suggested me to change the throttle body assembly. I was charged $1,000. The first day after I drive back to home. It happened again. I took the car back to dealer, left the car to dealer for one full week, Mechanics test drove the car for 210 miles at all condition, could not repeat the problem. Does anybody have the similar problem on your car? Any suggestion?
03-16-11, 02:47 PM
#26
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Ericko- it sounds like your gas pedal. I used to drive ups trucks and the newer ones have a drive by wire electronic pedal. Thats what happens when they start going out, you get no throttle and have to turn it off and restart to get it going. you dont get a code because the computer just sees no throttle. It wont last long like that/get one from a junkyard because its very expensive.
03-16-11, 07:44 PM
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I guess so,I just know that when my ups truck went bad id just push in clutch and turn off on and itd work again like he said. When I wrote it up it always came back as accelerator pedal replaced. It may be hard to get a proper diagnosis until it gets bad enough to fail for the mechanic. But id point them in that direction and have them test the pedal, it wont show a problem most times though.
To the op, you may be driving in sand and the rear tires start spinning. When this happens to me in snow it does the same. If its the slippery sand then its the same thing, the computers on the traction control and vsc shut off the throttle. It really sucks when you are pulling into traffic.
To the op, you may be driving in sand and the rear tires start spinning. When this happens to me in snow it does the same. If its the slippery sand then its the same thing, the computers on the traction control and vsc shut off the throttle. It really sucks when you are pulling into traffic.
01-30-12, 06:21 AM
#29
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Mass Airflow Sensor
Spent money replacing plugs, tps, cleaning throttle body with no success. Cleaned the MAS and noticed near instant improvement. After a few months, there is still a reluctance to fully take off, but it does not stumble anywhere near as bad as before. I have nearly been hit multiple times pulling out in front of traffic. Not sure if I need to replace the MAS to return it to normal.
01-04-14, 10:07 AM
#30
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I need help with my Lexus
I have a 1996 Lexus LS 400 never had any problems until now. I have changed only the battery and radiator, so the car has been really good.
1. The only problem I'm having now, is when I press the gas it takes the car about 5 seconds to accelerate. This only happens when I don’t come to a complete stop or come to a red light and then the light immediately changes.
2. Another problem, when I reverse sometimes the car shuts off.
3. Another problem when I press the gas or brake the car starts a bouncing move like a motor cycle and feels like it’s about the turn off.
Not sure what’s going on can anyone help me out?
1. The only problem I'm having now, is when I press the gas it takes the car about 5 seconds to accelerate. This only happens when I don’t come to a complete stop or come to a red light and then the light immediately changes.
2. Another problem, when I reverse sometimes the car shuts off.
3. Another problem when I press the gas or brake the car starts a bouncing move like a motor cycle and feels like it’s about the turn off.
Not sure what’s going on can anyone help me out?
