I have been recently for seeing some problems with my 98 USDM itr motor.
Here they are

1.When the car is cold...if you try to keep it at 1600 rpms ...it starts to fluxuate back and forth from 1600-1000 rpms...over and over.

2. When the car is fully warmed up...the fluxuating of the rpms goes away..and I can make it idle at 1600 no problems at all. However, a hesitation at low rpms starts to occur...almost as if the e-brake was on.

I know it has to be a sensor..however..what sensor are Temperature related? You can tell ....by the problems Im having..that they differe only by the Temperature of the motor.

Any help you guys can give me will be much appreciated

P.S I am getting NO check engine light.

 

I think all sensors are somewhat temp related. I think they use temperature and convert to voltage or something. For instance, an O2 sensor uses voltage, and converts that to an Air/Fuel ratio reading so we know what our AFR is. Or something like that. Dunno if that helps or not and I think I just confused myself

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RTW DC2 &raquo;</TD></TR><TR><TD CLASS="quote">I think all sensors are somewhat temp related. I think they use temperature and convert to voltage or something. For instance, an O2 sensor uses voltage, and converts that to an Air/Fuel ratio reading so we know what our AFR is. Or something like that. Dunno if that helps or not and I think I just confused myself </TD></TR></TABLE>
You succeeded in confusing me

As far as the problem goes-is the vehicle in question all stock?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b19coupe &raquo;</TD></TR><TR><TD CLASS="quote">
You succeeded in confusing me

As far as the problem goes-is the vehicle in question all stock?
</TD></TR></TABLE>Yes, Its pretty much all stock besides a JDM 4 TO 1 header, Carsound Cat, and 2 and half inch piping.
Geez, I swear..usually I can figure things out..but I cant figure out whats wrong.
Its always the most little things ..I know it.

 

Possible plugged cat. Or a glitch in the ignition system. When I get a weird one, I start with the basics.Check cam timing, ignition timing,spark plugs, wires-cap-rotor. Then start looking for loose connectors, vacuum leaks and so forth. If possible hook up a scan tool and watch your sensor readings on an all data list-see if any sensor is acting peculiarly when the problem occurs. Good luck.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b19coupe &raquo;</TD></TR><TR><TD CLASS="quote">Possible plugged cat. Or a glitch in the ignition system. When I get a weird one, I start with the basics.Check cam timing, ignition timing,spark plugs, wires-cap-rotor. Then start looking for loose connectors, vacuum leaks and so forth. If possible hook up a scan tool and watch your sensor readings on an all data list-see if any sensor is acting peculiarly when the problem occurs. Good luck.</TD></TR></TABLE>Thanks, I have been trying to figure this out for days..I guess ill try what you said. Im desprate any type of help
All though..thanks for the great info.

 

I think the $100,000 question is, why are you trying to get your engine to idle at 1600 rpm? I forget the exact stock rpm setting at idle, but it's around 750rpm. This could very well be the source of your problem.

Moving along, a bouncy idle when the engine is cold sounds like the IAC valve.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Batoutahell &raquo;</TD></TR><TR><TD CLASS="quote">I think the $100,000 question is, why are you trying to get your engine to idle at 1600 rpm? I forget the exact stock rpm setting at idle, but it's around 750rpm. This could very well be the source of your problem.

Moving along, a bouncy idle when the engine is cold sounds like the IAC valve.</TD></TR></TABLE>its not that Im trying to get to idle at that...its when I give it gas..and its gets to the rpms between 1500-2500...it cant hold a steady throttle..It starts to fluxuate the rpms back and forth.
Sucks really bad..cause I cant go really slow in 1st anymore..or the car starts to jerk back and forth..cause the throttle response goes up and down.

 

Ok, I understand now. I would place my bet on either the TPS or MAP sensors. They're both notoriously unreliable. Between the two, the symptoms sound like a bad MAP sensor. Howver, a bad MAP sensor will usually throw a CEL, whereas the TPS often does not. If you have a multimeter, you can check the appropriate voltages and resistances of these sensors. There are a couple of archived threads that explain the diagnostic process for these sensors.