Supra Forums banner

1 - 20 of 26 Posts

·
Registered
Joined
·
596 Posts
Discussion Starter #1
ok, so my tps went out on me after i dropped it.. so i replaced it with a brand new one from toyota, put it in, and adjusted it within spec using my ohm meter and using the resistance measures per the TSRM. I am still experiencing somewhat a high idle issue, at about 850-1000, it fluctuates sometimes. i have checked all vac lines, as almost all of my hoses are new. what else could be possible keeping my idle so high?
 

·
Registered
Joined
·
367 Posts
Aha. Another TPS trauma. If you read my post on the 87 sick supra, you will know I share your pain...I put the damned thing on just like you...well, maybe. I put it on, put the spacer at the throttle stop...the TPS showed full continuity so I rotated it clockwise until the continuity dropped off, then tightened it...that's the way I interpreted the manual...it says to turn it until the needle deflects...I've been through 2 and the car runs like sh*t...very rough idle, no passing gear, plus the transmission drops from first to overdrives right off the bat...and there is no throttle response when the d*mned thing is cold...if you get a clue, shoot me an [email protected] or anyone...thanks
 

·
Registered
Joined
·
596 Posts
Discussion Starter #3
well i dont have any lack of power issues, in fact the car runs fine, i dont have an auto tranny either so i need not worry about shifting problems. my problem is that it just idles high, not rough, i am just wondering what could still be keeping it high. before my old tps broke it used to idle perfectly at around 700-750, and now with the new tps that just isnt the case
 

·
Registered
Joined
·
367 Posts
TPS issues

apparently the TPS is an important and sensitive part of the system...I ran mine for a long time with the connection unplugged...and aside from bad gas mileage and lackof power...it ran pretty good...runs worse now with another tps plugged in!
 

·
Registered
Joined
·
5,231 Posts
Dire McCain said:
Aha. Another TPS trauma. If you read my post on the 87 sick supra, you will know I share your pain...I put the damned thing on just like you...well, maybe. I put it on, put the spacer at the throttle stop...the TPS showed full continuity so I rotated it clockwise until the continuity dropped off, then tightened it...that's the way I interpreted the manual...it says to turn it until the needle deflects...I've been through 2 and the car runs like sh*t...very rough idle, no passing gear, plus the transmission drops from first to overdrives right off the bat...and there is no throttle response when the d*mned thing is cold...if you get a clue, shoot me an [email protected] or anyone...thanks

I swapped in a 7M/auto back into my Sup...along with corresponding dash/body harnesses.

Since I was done, I still get a rear speed sensor error (tranny Code 61) and I used to get the TPS error, 'til I recently replaced it. The speed sensor is good and I even swapped it, the ECT, and ABS module when troubleshooting.... just still get the tranny code.

I get many of the same symptoms you have, along with lack of downshifting into 1st, when coasting to a stop. Hoping to F with the TPS again, when I install the FFIM in the next couple/few weeks. I am also replacinig the tranny fluid/filter and rear speed sensor. I am hoping that this triple-whammy fixes things, but I am also stumped.
 

·
Registered
Joined
·
375 Posts
idle control valve, stuck open take it out clean it wit some carb cleaner an get back on the road.
 

·
Registered
Joined
·
367 Posts
yeah, the TPS bit is the most frustrating damned thing I have ever dealt with...I get no codes...just dog sorry performance and incorrect shifting...I, too, am stumped.
 

·
Registered
Joined
·
596 Posts
Discussion Starter #9
Dire McCain said:
Idle control valve? Is that the one on the intake manifold that clicks and resets itself when you shut down?
yup, thats the thing, ill try cleaning it out tonite, and see if that helps.
 

·
Registered
Joined
·
620 Posts
If that fails, and you've checked and rechecked all idle components are working properly...remove the black plug from the throttle body and adjust the PCV bypass screw. A word of caution though... this can and will greatly affect vehicle runnability. Try 1/4 turn in (clockwise) then drive the vehicle for a day or so. Rinse, lather, repeat.
 

·
Registered
Joined
·
3,877 Posts
could also be your timing, ect ect ect...

there are a LOT of things that could effect idle, but the TPS is always a major pain on every car I've ever had to touch one on...
 

·
Registered
Joined
·
596 Posts
Discussion Starter #13
well i cleaned out my isc, but it wasnt even that dirty/clogged. i used some carb/choke cleaner to de-gunk it the best i could, and it didnt do shit. tomorrow i will test it using my ohmmeter, per the resistances in the TSRM and see if is up to spec. is there any other components that could be causing this other than timing? and i dont not want to adjust any screws that should not be messed with.
 

·
90T
Joined
·
460 Posts
Here's some things to look at:

0) make sure the TPS IDL-E2 contact shows low resistance (<2.3kohm) with 0.002 shim between throttle stop screw and lever
1) Check for any codes from the ECU
2) Check the ignition timing
3) check ECU temp sensor and thermostat. Does th car reach normal operating temps?
4) Check Vf and see what the ECU thinks is going on with your fuel trim
4a) If the fuel trim is rich, check for a vac leak. Since your idle speed is high and the ISC checks okay, then it seems likely you have a vac leak.
5) Check if your ISC is broken (replace with a loaner), or the ISC wiring is bad.

... these are less likely to be a factor...
6) Check the O2 sensor for cross-count spec
7) Check fuel pressure

That should keep you busy. :)
 

·
Registered
Joined
·
596 Posts
Discussion Starter #15
so i checked out my tps readings (again) and it checked out fine. there is no codes at all right now. i am unsure about the timing, it hasnt been done since ive had the car, but i have had no timing issues. my car does get up to operating temp and the t-stat work. i dont know about the fuel trim and all that shit.. i did check my ohm readings for my isc and i am getting a constant .025-.03 readings for B1-S1, and B2-S2. i know its supposed to be inbetween 10-30, so i am hoping that is my problem. anyone have any idea how much isc's run new from toyota?
 

·
Registered
Joined
·
596 Posts
Discussion Starter #17 (Edited)
well my ohm meter was set at 2k ohms.. i set it to 200 ohms and got a reading of 25, which is good. so i now know its not that

i also have no oxygen sensors at the moment, but it has been like that for a while, and i have never experienced idle problems.

i noticed today, when driving that it stays around 1200 for the first 2 mins of driving or so, then while im idling at a light or something it will slowly drop to about 1k. but that doesnt happen all the time. on my way home the idle never budged from 1200. and im still not getting codes im almost positive there is nothing wrong with my tps
 

·
90T
Joined
·
460 Posts
You should have a code 21 without an O2 sensor. I still think you should check the temp sensor. If the ECU get stuck in warmup mode you will stay in the fast idle mode.
 

·
Registered
Joined
·
596 Posts
Discussion Starter #19
i dont have any codes, i know how to check, and im not getting anything. i have been running no o2's for a while now, out of laziness, not by choice. im getting on it though, i shouldnt be running without them. i did check the temp sensor, according to the link you left per the TSRM, the resistances check out fine. Would resetting my ecu possibly help?
 

·
Registered
Joined
·
3,877 Posts
lack of an O2 sensor could cause all sorts of random problems...
 
1 - 20 of 26 Posts
Top