# Idles bad and hesitates when cold. **URL:** \ **Category:** SON240sx Automotive\ **Created:** [July 8, 2005, 6:03pm UTC](https://forums.speedlife.net/t/idles-bad-and-hesitates-when-cold/87040 "2005-07-08T18:03:33Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![B240](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/b240/32/5532_2.png) [@B240](https://forums.speedlife.net/u/B240)\ **Post date:** [July 8, 2005, 6:03pm UTC](https://forums.speedlife.net/t/idles-bad-and-hesitates-when-cold/87040/1 "2005-07-08T18:03:33Z")
91 240sx I have a problem with my car. When i first start my car it idles up and down between 600 - 1000 rpm for the first 5 mins or so, until i start driving it. Second when i first start driving i get a lot of hesitation. Can anyone give me a suggestion of what this might be before i go to the mechanic. Thanks. ---
**Author:** ![Ed1](https://avatars.discourse-cdn.com/v4/letter/e/958977/32.png) [@Ed1](https://forums.speedlife.net/u/Ed1)\ **Post date:** [July 9, 2005, 12:08am UTC](https://forums.speedlife.net/t/idles-bad-and-hesitates-when-cold/87040/2 "2005-07-09T00:08:02Z")
both my nissan 200sx and maxima is getting the same thing. water comes out of the exhaust from the 200… but after it heats up… all the idle problems are gone ---
**Author:** ![Racer\_XTREME](https://avatars.discourse-cdn.com/v4/letter/r/e47c2d/32.png) [@Racer\_XTREME](https://forums.speedlife.net/u/Racer_XTREME)\ **Post date:** [July 9, 2005, 7:46am UTC](https://forums.speedlife.net/t/idles-bad-and-hesitates-when-cold/87040/3 "2005-07-09T07:46:53Z")
Its your TPS. Throttle position sensor. ---
**Author:** ![Gonad](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/gonad/32/5481_2.png) [@Gonad](https://forums.speedlife.net/u/Gonad)\ **Post date:** [July 9, 2005, 7:54am UTC](https://forums.speedlife.net/t/idles-bad-and-hesitates-when-cold/87040/4 "2005-07-09T07:54:54Z")
> [@Racer X](#): > > Its your TPS. > > Throttle position sensor. I replaced mine and problem is still there. ---
**Author:** ![Jedi\_Car\_Fan](https://avatars.discourse-cdn.com/v4/letter/j/b9e5f3/32.png) [@Jedi\_Car\_Fan](https://forums.speedlife.net/u/Jedi_Car_Fan)\ **Post date:** [July 9, 2005, 9:00am UTC](https://forums.speedlife.net/t/idles-bad-and-hesitates-when-cold/87040/5 "2005-07-09T09:00:23Z")
Idle Air Control Valve… Its just a bitch to get @ on the KA or SR b series hondas are super duper easy ---
**Author:** ![Racer\_XTREME](https://avatars.discourse-cdn.com/v4/letter/r/e47c2d/32.png) [@Racer\_XTREME](https://forums.speedlife.net/u/Racer_XTREME)\ **Post date:** [July 9, 2005, 10:36am UTC](https://forums.speedlife.net/t/idles-bad-and-hesitates-when-cold/87040/6 "2005-07-09T10:36:47Z")
> [@Gonad](#): > > [quote=Racer X]Its your TPS. > > Throttle position sensor. I replaced mine and problem is still there.[/quote] Yours is different Gonad. I think he means hesitation when he first touches the gas when the car is cold, and then it accelereates normal. Have you ever thought about this Gonad, that you replaced a part with a part that was broken? it can happen, and it fucks up diagnoising really bad. And TPS is not a plug and play device, it requires adjusting. ---
**Author:** ![Gonad](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/gonad/32/5481_2.png) [@Gonad](https://forums.speedlife.net/u/Gonad)\ **Post date:** [July 9, 2005, 1:32pm UTC](https://forums.speedlife.net/t/idles-bad-and-hesitates-when-cold/87040/7 "2005-07-09T13:32:33Z")
> [@Racer X](#): > > [quote=Gonad][quote=Racer X]Its your TPS. > > Throttle position sensor. I replaced mine and problem is still there.[/quote] Yours is different Gonad. I think he means hesitation when he first touches the gas when the car is cold, and then it accelereates normal. Have you ever thought about this Gonad, that you replaced a part with a part that was broken? it can happen, and it fucks up diagnoising really bad. And TPS is not a plug and play device, it requires adjusting.[/quote] It has to be betwen 0.44 and 0.55v or some shit on idle and about 4.95v to 5v on full throttle if I’m not mistaken. And yes it requires adjusting. ---
**Author:** ![Racer\_XTREME](https://avatars.discourse-cdn.com/v4/letter/r/e47c2d/32.png) [@Racer\_XTREME](https://forums.speedlife.net/u/Racer_XTREME)\ **Post date:** [July 9, 2005, 6:45pm UTC](https://forums.speedlife.net/t/idles-bad-and-hesitates-when-cold/87040/8 "2005-07-09T18:45:54Z")
> [@Gonad](#): > > [quote=Racer X][quote=Gonad][quote=Racer X]Its your TPS. > > Throttle position sensor. I replaced mine and problem is still there.[/quote] Yours is different Gonad. I think he means hesitation when he first touches the gas when the car is cold, and then it accelereates normal. Have you ever thought about this Gonad, that you replaced a part with a part that was broken? it can happen, and it fucks up diagnoising really bad. And TPS is not a plug and play device, it requires adjusting.[/quote] It has to be betwen 0.44 and 0.55v or some shit on idle and about 4.95v to 5v on full throttle if I’m not mistaken. And yes it requires adjusting.[/quote] Yeah, there is another way to do it too, either way it just takes trial and error tuning. B240 is describing classic TPS symptoms (see the other thread about idling for the explaination). Blah, maybe ill make a post about what to do if your idle is messed up. Here im going to rant here. If your IDLE is Fuct! If your IDLE is going up and down its a sensor issue because the ECU is controlling the cold air valve. If this only happens once the car is warming up. The main sensors that effect that would be, the TPS, MAFS, coolant Temp. TPS problems will make the car idle up and down at startup and will alos cause a hesitation when stepping on the gas because the ECU will compensate with a little extra fuel when you start to press on the throttle, but no TPS then it doesnt know when you touched the throttle. MAFS, if you mafs is messed up, you will know because it will idle like shit and you will not be able to rev past 2400rpm. Coolant temp tells the ECU when the car is warmed up completely. If its broken the car will never warm up according to the ECU, and will enhance idle issues no matter if the car is warmed up or not. Also, check your grounds and add more grounds if nessesary, grounds help the sensros do their job, and give accurate readings. … k thats all i got right now, if i forgot something let me know. ---
**Author:** ![Sven](https://avatars.discourse-cdn.com/v4/letter/s/e47c2d/32.png) [@Sven](https://forums.speedlife.net/u/Sven)\ **Post date:** [July 13, 2005, 6:10pm UTC](https://forums.speedlife.net/t/idles-bad-and-hesitates-when-cold/87040/9 "2005-07-13T18:10:22Z")
^^^ Write it up for the FAQ board and someone will sticky it then we can just refer them to there instead of explaining this over and over again! ---
**Author:** ![Ed1](https://avatars.discourse-cdn.com/v4/letter/e/958977/32.png) [@Ed1](https://forums.speedlife.net/u/Ed1)\ **Post date:** [July 13, 2005, 6:28pm UTC](https://forums.speedlife.net/t/idles-bad-and-hesitates-when-cold/87040/10 "2005-07-13T18:28:12Z")
TPS = ? ---
**Author:** ![Sven](https://avatars.discourse-cdn.com/v4/letter/s/e47c2d/32.png) [@Sven](https://forums.speedlife.net/u/Sven)\ **Post date:** [July 13, 2005, 6:32pm UTC](https://forums.speedlife.net/t/idles-bad-and-hesitates-when-cold/87040/11 "2005-07-13T18:32:44Z")
Throttle Position Sensor