I'm not quite sure how to explain it so if anyone knows what I'm talking about, or has experienced this as well..your input is greatly appreciated. Whenever I start my car cold, I warm it up for about a minute..then shift into R. That's when it seems like the engine dies/cuts in and out. This only happens when the car has usually been sitting around for 4+ hours without starting it. Oh BTW, I have a '03 TL-S. Thanks in advance.

 

Ambient Temp Sensor??

 

Does it also do the same thing when you put it in any other gears? How about vibrations and/or bogging (as in low rpms, engine is about to die) as you are coming to a stop?

 

It slightly happens when shifting into D..but its most noticeable when shifting into R. As for my RPM's bogging at lower speeds..the needle does seem to jump a bit when braking/coming to a halt.

 

Could you elaborate a bit more on this Tom?

 

That sounds normal. What I'm talking about, you would definitely feel it because the RPMs drop to 300 and the car feels like it's about to bog down and die.

Well, I don't know what to tell you, Brian. It could be the transmission, maybe?

 

No, I haven't experienced my RPMs dropping even near 300. Hhhmm...does not driving my car have anything to do with my problem? I have been on vacation in Atlanta and haven't driven my car for about 1 1/2 months. And I hope its not the tranny b/c I only have 10k miles on my car. :'(

 

does anyone have the problem where the RPM moves by itself at any gear?? it only happens when the engine is cold or hasnt been runnin for 4+ hrs... is this the same problem as u ill*tl??? my car actuallys jerks forward while the RPM jerks also.... does it in all gears except R and N.

 

ill-

This might be totaly off base but if the Ambient Temp Sensor was going bad it would give the wrong info to the ECU which in turn trims the fuel delivery to the injectors. For instance: If the sensor gives a reading of the air being 10 degrees F outside at startup and it's really 70 deg. the ECU will practicaly flood engine with more fuel than it needs till warm up temps are achieved.

I'm not sure if a bad ATS would throw warning light or not.

 

mine does it only in reverse and its gotta be cold no matter what time of day i was thinkin tranny but i need to make and appontment and take it in

 

I thought the PCM monitors the CTS (coolant temperature sensor) for coolant temp to determine what mode the engine should be running in. If too cold, the engine will run in open-loop mode and the idle rpm would be much higher. Otherwise at normal operature temp, the engine will run in close-loop mode to keep the emission at the minumum level. The coolant temp is a better indication of how warm or cold the engine is.

 

Edward-

That's true, it does. But the sensor has to send the right information to the PCM for it to make the right changes.

It could be either of the two, the ATS or the CTS. Still the right info has to get to the computer.