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TPS adjustment

33K views 36 replies 6 participants last post by  Jshill76 
#1 ·
Hey people,

I was driving down the road, when I stepped on the trottle to over take someone, suddenly the car budges, or stops accelerateing I'm surprised so I let go of the throttle. In a split second the car starts to accelerate alone till redline, I put it on neutral and stop on the side of the road.

Anyway after turning the car on again I realized everytime I go over 30% on throttle, the car does the same thing over and over...

My friend said it was the TPS, and I believe he is correct cause I had one damn screw holding my TPS!!! The second one was gone...

My question is how can I adjust it back to normal?

Car: IS300, Automatic transmission, with an Aristo 2JZGTE swap.
 
#2 · (Edited)
Yes, you can adjust the TPS back and you must otherwise your DBW might fail and the car will go into limp (safe) mode. You will need a voltmeter/digital meter($10 meter will work) to either probe the the white/red wire or read the pin at the ECU to ground. I've used a tiny needle to pierce the wire's insulation and then put my meter test lead on that, leaving no damage or a use a back probe which reads at the connector and is best(either way works). This thread tells you how, post 8. I surprised it didn't throw a DTC but it may have only moved a bit i guess.

http://my.is/forums/f90/tps-adjustment-400848/

You will also need to replace the other screw and make sure the sensor is secure. There definitely needs to be two mounting screws. The Lexus/Toyota part number is 90079-11021 for the TPS mounting screws.
 
#3 ·
I can't get a throttle response anymore! I put 2 screws and reinstalled the tps, I couldn't get any response from throttle whatsoever... the car turns on tho, not stable but turns on, I tried fiddling with how I am mounting the TPS onto the throttle the car stopped turning on, which means the first time was correct, but no throttle response and my SAFC says zero throttle...
 
#8 ·
I gotcha. I guess i should've mentioned that first and it makes sense why you couldn't dial it in(you must have never been against the valve). The trick is to mount it with the screws loosely at the farthest clockwise position. Hopefully the next update will be good:)
 
#15 ·
I would verify and use an OBD2. Dial in the TPS until you read a throttle opening of 14.8 +/-.8. I would make sure you have a good test lead connection at the W/R and B wires and at fully clockwise to counterclockwise, you should be able to turn till you have a voltage of about .65 volts. You should to be able to feel a hesitation after it engages while turning.

The part is about $90 at Sewell but that's before our discount, search this part number and you can get it cheaper. Get OE replacement from Rockauto. Only is it's truly bad.

8945230150
THROTTLE POSITION (FOR E.F.I.) SENSOR

$57 link for OE replacements
2002 LEXUS IS300 Throttle Position Sensor (TPS)
 
#20 ·
I installed it, also same problems showing on the voltmeter, I guess the adjusting method for the 2jzgte is different...

What is the basics of adjusting a TPS? cause the 0.65 till 0.70 is not working for me since my car reads 1.211 till 2.000 which means I'm too far from the correct voltage...
 
#21 ·
Have you tried the OBDII method? My meter wouldn't read correctly either ...
 
#24 ·
If you have an Aristo setup, i don't think you have a DLC3 or OBD2 port. If you do you that ability, check under realtime data and under throttle opening. From there it should give you the running throttle position and it should be 14.8 +/-0.8%
 
#26 ·
Just a small update cause I didn't find any live data readers close by me...

A friend of mine came to check what was going on, we loosened my throttle body's cable and it reduced the reading on my SAFC2 till 0.0% while it was stuck on 24% all the time before. now whats going on is the following...

while opening the throttle body by hand while the key being (ON) I hear a clicking or ticking sound inside the throttle body.

Why am I mentioning the ticking? well because when I reach full throttle while the car is on ON. something inside the throttle body makes a double ticking sound, and when that happens and we let go of the throttle body it doesn't go back to 0%, it goes back to 10% as if its getting stuck.

the timeline is like this for the rotating.

1. Throttle body on 0%
2. We open throttle body till 10% (a ticking sound happens at 10%)
3. We continue to open throttle till 75% (another ticking sound happens, and now we're WOT)
4. We let go, so that throttle can close again but it doesn't (it gets stuck on the first tick which is 10% throttle or the first tick/click whatever you wana call it)
 
#27 ·
Just to be clear we're talking about a Aristo throttle body which has a opposite setup from what I've read. I'm not even positive what percentage the TB is supposed to be open at idle, is it the same(14.8%). I have no idea what that ticking means, i know when you turn the stock GE's accelerator pedal position sensor/wheel, the throttle control motor turns the butterfly and is rather loud when doing so. I don't want folks to get confused that this is not a stock 2JZGE engine.
 
#28 ·
My has the same behavior.

1) Key turn to on position.
2) Reads 14.5 on OBDII
3) Open throttle by hand, then release cable.
4) TB makes buzzing sound
5) OBDII reads 13 something I think

I assume that was normal behavior.
 
#30 · (Edited)
Having trouble setting my aristo tb/ge tps. i swapped my old one for a polished one and moved the maf into the intercooler pipe. set the tps at .65v and it won't idle for shit. it will run if i give it gas but it sputters really bad. when i let off it will idle too slow/jerky then dies out. this is the second time i try to install this thing, first time i put my old one back on and set the tps with minimal issues. i didn't even use a volt meter that time, just moved it until it idled like i wanted it to. can't seem to find any spot this thing likes.// Today I put the old TB back on and set the TPS to .65.. started and idled fine.
 
#35 ·
I cleaned the mesh screen inside thoroughly, but nothing changed, same problems still happening.

Now I have the following codes:

P1349
P1346
P0300
P0301
P0302
P0303
P0304

I will replace the OCV soon. Because I have seen some responses that some people did actually test it using the method described in your link above, and it was perfect even when the car was warm, but still had problems, and when they changed it, everything went back to normal.
 
#36 ·
The tests i have posted have pretty much come from the FSM, almost word for word. Maybe those members who didn't notice a difference did not do the test right or wait till the car was fully warmed up. There should be a distinct difference when power is applied to the OCV. Download the FSM and diagnostic manual from the stickies if you don't already have them. P1346/P1349 like i mentioned is almost always the OCV, which can make your car misfire or throw a random misfire dtc. Even though the screen is clean does not mean the spool in the valve is shifting properly.
 
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