i own a 1987 toyota supra turbo 5 spd and the idle for warm and cold is around 1000-1100 how do i adjust that thnx guys...
idle speed
- Thread starter donovan
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well i furgured it out there was this screw but you know on the right side of the throttle body where the linkage is and stuff well u know where it hooks up to the parts that make the inside of the throttle body move open well u know where the valve is under all that linkage what is that for?
That screw is for idle speed, but I wouldnt mess with that, check the calibration on the TPS first.donovan said:
also, check the ajustment on the dash pot on your throttle body
I think that is the stop screw for adjusting the TPS you are talking about. The TPS could need to be adjusted. Have you checked in front of the TB there is a black plug/cover about 1/2" round. You can pop that cover off and there is a screw inside. If the previous owner messed with that screw, like unscrewing it, it would maybe increase the idle. The ISC can be checked to see it it is working right, just check the TSRM. If it's not it will keep adding some extra fuel after the car is warmed up. It could also be your Temp. sensor, feeds the signal to the ECU after it's warmed up and it's not kicking the idle down.
No, thats not the ajustment for the TPS, you ajust the TPS by turing the TPS... you stick a multi-meter on the idl and E2 pins on the TPS...when it read cont. then your TPS is in spec.AJ'S 88NA said:
its not going to be the temp sensor, and most likely not the ISC either
the temp sensor has nothing to do with "kicking the idle down"
oh, and not to be an ass or anything, but dont post help unless you are 100% sure what your talking about....if you give them the wrong info then your likely to steer them in the wrong direction and take them even longer to solve their problem.
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The little screw he is talking about on the back side of the TB is for adjustment of the TPS. You have to adjust it with a feeler gauge to get it set right to adjust the TPS with the ohm meter. Doesn't ISC stand for Idle Speed Control? The temp sensor senses the temp to set the idle down after it warms up doesn't it? Please correct me if I Am wrong.x87SUPRA87x said:
Sorry I meant the CSI, Cold start injector or the cold start injector time switch, easy to check with a ohm meter.
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Sorry for the misunderstanding, I thought you were talking about he screw thats on the front of the TB. The screw on the back is the throttle stop screw, you have to put a feeler gauge inbetween before checking the TPS dont mess with that screw either...actually ajusting it is done how I mentioned above.AJ'S 88NA said:
The ISC does stand for Idle speed control, but controls it in a different sense, it regulates the amount of air entering the engine during idle and other times during the time the motor is running..it also helps keep the motor going when you floor it the fully pull off the gas by slightly curving the air drop off.
If the ISC is really on its way out or gummed up the perormance will really lag, as long as his car is running good, thats most likely not his problem. Plus for the ISC on supras to go out is pretty rare.
I did mention the screw on the front of the TB. If somebody has "unscrewed" it, it would cause the car to idle faster. I thought that was his question how to get the car to idle down? I guess maybe I'm the one that has misunderstood?x87SUPRA87x said:
It's easy to check those with a ohm meter and I know they don't normally go out, just trying to elimate possible problems
don't mess with any of the damn screws on the throttlebody, OK?
they where capped form the factory on the 89+ models just because of this.
idle is controlled through the idle control stepper motor, and if it's loaded with crap it can idle high.
if you're timing is off, it will idle high
if the TPS is off...yep you guessed it
screwing with any of the factory preset screws is a recipe for disaster as getting them back where they belong is close to impossible...
they where capped form the factory on the 89+ models just because of this.
idle is controlled through the idle control stepper motor, and if it's loaded with crap it can idle high.
if you're timing is off, it will idle high
if the TPS is off...yep you guessed it
screwing with any of the factory preset screws is a recipe for disaster as getting them back where they belong is close to impossible...
THIS IS VERY TRUE!
Mess with it enough and you'll find you're self stranded one day because it wont turn on... or it will start turning off on you when you let go of the gas. As i still have not found where it goes with weeks of messing with it... because it takes time for the comp to learn it.
Could be one of the reasons that i found the car in the junk yard LOL
Mess with it enough and you'll find you're self stranded one day because it wont turn on... or it will start turning off on you when you let go of the gas. As i still have not found where it goes with weeks of messing with it... because it takes time for the comp to learn it.
Could be one of the reasons that i found the car in the junk yard LOL
It will also idle high if you have a vacuum leak. In addition to what others have said, check all of your vacuum lines to make sure none of them are cracked. It doesn't take much of an air leak to raise your idle. This was my issue...