This True? Playing with TPS

[CozmoNz]

I headed up to the local garage the other day, (picking up the Uno after it had a Wof done on it - Passed btw).

anyway, while i was waiting i had a chat to the *tuner* chap, (the one that does carbie readjustments, cambelts, emission testing, basicaly all the tehcnically nitty grittys, while the other chaps do the bigger stuff).

anyway, i mentioned *yeh, i need to fix my TPS*, he basically slapped me in the face and said not to touch it.

I didnt understand, so of course, i asked.

the responce was that *they are set on flow benches, so its not a default setting, its different for each engine*.
and *we have already had a few in here, from these "forums" of people playing with their cars, without knowing what they are doing, and end up breaking them*.

so i went with it

*what do i do then?*
*either get a new TPS sensor, or rebuild the old one, theres carbon contacts within the unit that wears out after a while, that is, if thats the problem*.

So back to square one.

Jerk upon throttle liftoff, is caused by the Tps - Yes?
do they just wear out and cannot be readjusted? or is he just looking for more cash for his back pocket?

He also said that *my car* has problems with the ecu also... ive never heard of this happening! is this true?

revhead, im lookin @ u

someone help cozzy mo

[Lloyd]

TPS can be faulty, but you do somtimes need to adjust them anyway. Set on flow benches? I think you must have heard something wrong

[Crimson Tears]

Bullshit, you set the TPS according to spec using the service manual. The TPS doesn't have anything to do with flow, it sends a voltage signal to the ECU which tells it the position of the throttle. I can understand what he's saying, people playing around with them not knowing what they're doing, but provided you set it up correctly, there should be no problem. Maybe he thought you were talking about the idle speed control valve.

[sopachrga]

I had a quick word to my mechanic (family friend) and he seemed to think that is a lie. He said the AFM's are set up on flow benches, and should not be adjusted, like some people who think that it is a good idea to turn the gear on them forwards a couple of teeth.

[dotdog]

Carbon Contacts on a TPS umm no, this would not work very well. Ive changed and adjusted TPS on my starlet a few times when i have changed throttle bodys. When you get it wrong the car is very jerky when coming on and off throttle, ive got it set right now and its smooth as

[Bazda]

I had a quick word to my mechanic (family friend) and he seemed to think that is a lie. He said the AFM's are set up on flow benches, and should not be adjusted, like some people who think that it is a good idea to turn the gear on them forwards a couple of teeth.

yes it is a good idea, had to do it to mine , few clicks richer.

[Mr Revhead]

the ecu probs hes talking about are probably the ae101 20v. they are knowen to shit the ecu and afm from time to time.

as with anything, dont dick with it unless you know what you are doing, sounds to me as if was talking about the afm.

bazdas application is bit different form your 20v so dont do it!
not that you can on a b/t.....

[Bazda]

yea prob dotn wana touch your one if the car is standard, if yoru goan do cams etc then u might wana start playing with it then.

[BZG Wagon]

I was told it was a standard reading from a Mechanic at Albany Toyota.

I get that $&#$% jerk when you lift-off the gas, and he seemed to think it was more like a problem with quad carbs, which was not even worth thinking about touching.

[Dr-X]

as with anything, dont dick with it unless you know what you are doing

I dont agree with this - it's mucking aorud in unfamiliar territory that teaches us the quickest ways to do and not to do stuff. Just try to have a good workshop book handy, and be prepared to take it to your mechanic when all else fails.

[fangsport]

as with anything, dont dick with it unless you know what you are doing

I dont agree with this - it's mucking aorud in unfamiliar territory that teaches us the quickest ways to do and not to do stuff. Just try to have a good workshop book handy, and be prepared to take it to your mechanic when all else fails.

...............and have the repair cost 3 times as much????????????????????

[Mr Revhead]

dr-x, theres this thing called common sense.... you should know your own abilities. anyone with half a brain should know what they are or are not capable of....

[Dr-X]

I can tell you with no previous mechanical knowledge I changed the clutch and CV joints (aswell as various incidentals such as a slave cylinder, caliper rebuilds, etc) and didn't have a problem.

IMHO, saying you sohuldnt work on you're own car if you're not certain what you're doing is pessimistic, and doesnt encourage people to have a go. But hey, it's not like I didn't expect some specific people to argue with that

[Mr Revhead]

take it however you will, iv got better things to do than spell it out to you.

please stop spamming tech

[rolla_fxgt]

Cozmo mine was doing that, had a mechanic friend who works at toyota have a look at it, turns out it wasnt the tps at all, it was my o2 sensor, basically they get all covered in crap everynow & then & i just took it down to that auto electrical place by bridgeman street & they put it on the rolling road & readjusted it to work the air fuel mixes propperly with the throttle position & now it works fine, except lately when really cold, so i think i might have to go back soon. But its been 3 years between trips, check this 1st its apparently a common fault that trips up the tps

[Perky]

FWIW I have a similar problem with a slightly jerky throttle and cold running issues. There is an error code for the O2 sensor and the Toyota workshop have confirmed that it is faulty and probably the cause of the problem.

The TPS setting measures correctly, and the range of adjustment over which it should measure correctly is really small, so I'm not inclined to mess with it.

I've had this problem for a while but it hasn't been so bad since the car had a good run around the South Island. I really must do something about it though. The Toyota sensor apparently costs over $300. I'm told that Bosch parts are available for half that. I'd be keen to pick one up second hand -- does anyone know a good source?

[Lloyd]

The annoying thing about the Toyota sensors are the fact that there is a flange as part of the sensor. A lot of the generic ones you can get are threaded. If you really want you can make up a flange and weld a nut to it if you want to get a threaded one over a genuine one. I ended up doing this and it worked out nicely

[The_Lorax]

Hrm.. I have a similar problem with my aw11. The car jerks on acceleration/deceleration, and I get poor fuel economy (60-70kms to $10 of 96 with open road driving)

I've checked the coolant temp sensor with a multimeter (working fine), and an ECU diagnostic shows no error codes.

I'm going to check that the TPS is working properly with a multimeter and check for sluge in the assembly. My podfilter is full of 20 years of crud, so I might replace that as well.

All this talk of faulty o2 sensors causing a jerky throttle got me wondering if my o2 sensor isn't working properly. How can I test it?

[rolla_fxgt]

I cant remember if u can test it as such, i think its just an assumption if all else is not coming up faulty. like sticky throttle cable, no error codes.

Mr Rechead might know more about it.

But all i know is involved a little reprograming of the ecu & the settings on it.

But yeah eventually i'll need a new o2 sensor too, unfortunately its one of those parts that get worn out.
Who puts a sensor in the exhaust anyway? It seems a stupid place for it to me anyway.

[Ae92typeX]

Hrm.. I have a similar problem with my aw11. The car jerks on acceleration/deceleration, and I get poor fuel economy (60-70kms to $10 of 96 with open road driving)

70km 10 $10 aint that bad. $10 96 is only 7 litres now so thats still 10km L