12 replies to this topic

[acoustic]

I seem to have a flat spot in my accelerator that is causing a lurch. My RX is a 99 and my mechanic seems to think I could have a flat spot in my throttle position sensor. It happens just off of idle where it seems to loose gas and then bam it kicks back in causing a lurch or a hesitation. He has not had a chance to OHM test my throttle position sensor but said he has seen a couple wear out and develop a flat spot near idle because this is the position it rests in?? Has anyone else had this issue? If you are in neutral and step on the gas it hesitates then kicks in like it's bogging then catching up.....

-Acoustic

[dal]

I had similar idle fluctuations in my 99RX with 107k miles. In P or N, the idle was varying levels, but not to a level of lurching. My symptoms were more of moving from P to R or N to R/D when it would lurch on most occasions. Check engine light was on and off for about a thousand miles. Last week, throttle position sensor was replaced (along with 2 oxygen sensors) and all symptoms have gone away. Smooth shifting and much smoother idle. I think TPS was about $100 and less than an hour to install at an independent shop. A lot less than the O2 sensors.

[RX300 Steven]

I have a 2000 RX AWD and need to replace my throttle position sensor... ECU is continuing to report it bad after a few resets. Where is this hiding on the TB ? does anyone have a pic of it's location ? Any warnings on replacing this sensor with a new one ?
Thanks

[RX300 Steven]

I replaced my throttle position sensor today. Was actually pretty easy to do and save me a hundred bucks or so from the shop. Hardest part was that it's on the back side (firewall side) of the intake into the TB. Just needed a small screw driver to get back there and a little patience. No more check engine light and it actually runs very smooth now and shifts very smooth. Guess I didn't really notice it getting worse over time until I have replaced it. Now it's like brand new again on idling, accelerating, shifting maybe even getting better gas mileage now... I think with the bad sensor it was idling a little too high sometimes and that eats up gas over the long run.
I really noticed a difference in shifting from park to D or from neutral to Drive... no noise, or jolt, or anything, just goes into gear and drives away.

[artbuc]

I replaced my throttle position sensor today.   Was actually pretty easy to do and save me a hundred bucks or so from the shop.  Hardest part was that it's on the back side (firewall side) of the intake into the TB.   Just needed a small screw driver to get back there and a little patience.   No more check engine light and it actually runs very smooth now and shifts very smooth.   Guess I didn't really notice it getting worse over time until I have replaced it.   Now it's like brand new again on idling, accelerating, shifting maybe even getting better gas mileage now...  I think with the bad sensor it was idling a little too high sometimes and that eats up gas over the long run.
I really noticed a difference in shifting from park to D or from neutral to Drive...  no noise, or jolt, or anything, just goes into gear and drives away.

Steven, I'm getting ready to check-out the TB sensor on my 99 RX. My shop manual gives the following instructions for installation: With throttle valve fully open, insert the TB sensor to the throttle body with it turned clockwise by 30 to 60 degrees against the fully-open valve position. Then, torque the sensor by turning it counterclockwise.

Did you follow this rotating/torque procedure? I assume you have to do this to make sure sensor does not bottom-out at full throttle.

Finally, can you give me the Toyota part number for the sensor? Thanks.

[RX300 Steven]

The throttle position sensor has two mounting screws to remove and then it will rotate 15 degrees counterclockwise. Just remove the last screw slowly and hold on to the sensor. Then when you put the new sensor on, it goes back on in the exact same 15 degree counterclockwise turn and then you turn it back clockwise to line up with the mounting holes. Basically that is the torqueing process. I read some postings that on other Lexus models you have to calibrate/adjust the sensor mounting position, but the RX mounting holes are fixed, no way to adjust. The sensor is keyed so that it can only go on 2 ways, the right way, and 180 degrees the other way and the holes don't line up that way.
I throttle post (whatever it is that pushes inside the sensor) is spring loaded, so when you push the sensor on and turn it clockwise to line up the mounting holes that is the torquing that you are referring to.
I don't have the number handy, I just picked it up from AutoZone.. It was a Wells name brand around 50 bucks. They did list another brand for 34, but were out of stock. $50 was still better with maybe a whole 15 mintues my time then taking to the dealer.

[mikey00]

I replaced my throttle position sensor today.   Was actually pretty easy to do and save me a hundred bucks or so from the shop.  Hardest part was that it's on the back side (firewall side) of the intake into the TB.   Just needed a small screw driver to get back there and a little patience.   No more check engine light and it actually runs very smooth now and shifts very smooth.   Guess I didn't really notice it getting worse over time until I have replaced it.   Now it's like brand new again on idling, accelerating, shifting maybe even getting better gas mileage now...  I think with the bad sensor it was idling a little too high sometimes and that eats up gas over the long run.
I really noticed a difference in shifting from park to D or from neutral to Drive...  no noise, or jolt, or anything, just goes into gear and drives away.

Steven, I'm getting ready to check-out the TB sensor on my 99 RX. My shop manual gives the following instructions for installation: With throttle valve fully open, insert the TB sensor to the throttle body with it turned clockwise by 30 to 60 degrees against the fully-open valve position. Then, torque the sensor by turning it counterclockwise.

Did you follow this rotating/torque procedure? I assume you have to do this to make sure sensor does not bottom-out at full throttle.

Finally, can you give me the Toyota part number for the sensor? Thanks.

I don't have the Toyota part #, but you can get OEM Lexus throtle position sensor from newlexusparts.com for $44, no tax and free shipping.

[acoustic]

I don't have the Toyota part #, but you can get OEM Lexus throtle position sensor from newlexusparts.com for $44, no tax and free shipping.

[/quote]



I just checked newlexusparts.com and they claim to be a Lexus dealer but I highly doubt it! Read the line below I copied and pasted from the main page of the site. It's newlexusparts.com's mission statement....

"It is are mission to provide an extraodinary automotive purchase and ownership experience"[B]


This is the kind of crap that really ticks me off. A real Lexus dealer would know the difference between the word OUR & ARE. Pull up the "contact us" page and you don't even get a physical address! No thanks I'll pay a little more and purchase from my local Lexus dealer. In my estimation this company is nothing more than one of those fake Rolex distributors...... Just my .02...

-Acoustic

[rlin78]

You are right, I don't trust newlexusparts.com, and their site is very slow at times. irontoad.com offers genuine toyota parts at a good price. you can also pick up an oem TPS at partsamerica.com for about $30

[mikey00]

You are right, I don't trust newlexusparts.com, and their site is very slow at times.  irontoad.com offers genuine toyota parts at a good price.  you can also pick up an oem TPS at partsamerica.com for about $30

newlexusparts.com is actually Park Place Lexus, 1025 Preston Road, Plano,Texas.
I have purchased many parts from them as well as irontoad.com which is actually Thomson Lexus, 50 Swamp Road, Doylestown, PA. Irontoad will get you just about any part if you do a request but what I like about newlexusparts.com is they have just about every Lexus part available listed with prices on the site.

[rlin78]

You are right, I don't trust newlexusparts.com, and their site is very slow at times.  irontoad.com offers genuine toyota parts at a good price.  you can also pick up an oem TPS at partsamerica.com for about $30

newlexusparts.com is actually Park Place Lexus, 1025 Preston Road, Plano,Texas.
I have purchased many parts from them as well as irontoad.com which is actually Thomson Lexus, 50 Swamp Road, Doylestown, PA. Irontoad will get you just about any part if you do a request but what I like about newlexusparts.com is they have just about every Lexus part available listed with prices on the site.

So you are actually getting parts that are made by Lexus/Toyota if you order from newlexusparts.com?

[mikey00]

You are right, I don't trust newlexusparts.com, and their site is very slow at times.  irontoad.com offers genuine toyota parts at a good price.  you can also pick up an oem TPS at partsamerica.com for about $30

newlexusparts.com is actually Park Place Lexus, 1025 Preston Road, Plano,Texas.
I have purchased many parts from them as well as irontoad.com which is actually Thomson Lexus, 50 Swamp Road, Doylestown, PA. Irontoad will get you just about any part if you do a request but what I like about newlexusparts.com is they have just about every Lexus part available listed with prices on the site.

So you are actually getting parts that are made by Lexus/Toyota if you order from newlexusparts.com?

Yes, genuine Lexus part. They are a Lexus dealer selling parts over the internet cheaper then what you would pay if you walked up to their parts counter.

[acoustic]

OK I changed my throttle position sensor and I still have the flat/dead/lag spot in my throttle response. I even reset the ecu by disconnecting it. I purchased the tps from my local Lexus dealer for $56.00. When I asked for the Toyota club discount my old dealer in NH used to give me the guy just automatically gave me 20% off. All you need to do is ask!! Could it be my knock sensor is bad and severly retarding the timing???