96 lesabre trouble

when i start the car up in cold weather it idles very fast but when it should start to idle down it doesnt.... i can shut the engine off and start it again the idle is normal.... in warm weather i have no problems with this... one guy told me it could possibly be one of the sensors... any help would be greatly appreciated...thanks

The sensors on a cold start are as I understand.

MAF Mass Air Flow (just past the air filter)
ECT Engine Coolant Temp (near the thermostat)
TPS Throttle Position Sensor (throttle body)
IAT Intake Air Temp (Just before the throttle body )

How quickly do you restart? How warm did you let it get?
Do you touch the throttle at all?

I suspect the MAF. Only because it actually heats up during a quick start. The other sensors are more passive during their startup data collection. IF,, its a sensor.
Try disconnecting the MAF sensor just behind the intake filter and try it on the next cold day.

Interesting .. I will suscribe to this post. .

Good Luck

The sensors on a cold start are as I understand.

MAF Mass Air Flow (just past the air filter)
ECT Engine Coolant Temp (near the thermostat)
TPS Throttle Position Sensor (throttle body)
IAT Intake Air Temp (Just before the throttle body )

How quickly do you restart? How warm did you let it get?
Do you touch the throttle at all?

I suspect the MAF. Only because it actually heats up during a quick start. The other sensors are more passive during their startup data collection. IF,, its a sensor.
Try disconnecting the MAF sensor just behind the intake filter and try it on the next cold day.

Interesting .. I will suscribe to this post. .

Good Lucki drive for about 1 mile and then shut it off and then restart and then is fine. i do not touch the accelerator. so is it just like a plug or something that i diconnect? thanks alot appreciate it

Yah just a plug.. It has plastic you have to pry back to let it come off..

Hope this works.. but if it dont.. its eliminated, and we are further along.

Your disription of how long you drive it makes a bit of a thought change. Im a bit confused how you can drive a mile without touching the accelerator.. but anyway we kindof took the path of the sensors from your first post.

The CTS or I noted I typed ECT.. yah ECT. this is sensing the temperature of the coolant in the engine, not whats in the radiator, the coolant circulated in the engine and the thermostat adds cooler fluid as it opens when it gets hot.
It also runs your guage.

Has your temp guage working normally?
Perhaps we are dealing with a thermostat problem when its still pretty cool. It would make sense since when you stop the engine heats up a bit since the coolant stopped circulating and that thermostat gets much hotter and can open and if its sticking a bit and snapping open after you stop after a mile it could be the whole problem.

This could be your thermostat is stuck open or sticking. It would be lucky if this is it. Its a very cheap fix.
But, lets just take one thing at a time.

Good Luck. Ill be waiting.

Bass

first let me say thanks for all your replies!!! ok the first thing i did was start the car and it was running like a race horse so i shut it off.. then i unplugged the sensor and plugged it back in, then restarted it same thing idleing fast as the first time.. so i unplugged it and started it with it disabled same thing... then tried plugging it back in and trying again and no luck....... i let the car run for about ten minutes (idleing fast) shut the car off and immediately restarted it and was like it should run "normal".... i think you misunderstood me about the throttle lol i dont hit it when the car is in park only to actually drive the car and another crazy thing when i am driving the car when it is idleing fast its like the car is on cruise control when i let off the gas lol??? somebody once told me that to find out if your thermostat is not working to feel the top hose to the radiator and if the hose is hott its working and if cold isnt working..ever hear of that??? thanks again

Regards to the thermostat... They are correct that if its hot its open, however if its open all the time the engine cannot regulate the temp from 180 degrees to 200 approx.

The MAF sensor isnt the problem.. Good to know..

Here is a try.. Lets reset the computers memory.

To do that you just have to disconnect the battery terminal to the battery for 10-20 seconds.
This is a good starting place anyway, without jumping to conclusions.

If the problem goes away.. were good..
If not.. then..

After running for a couple trips to the store and such it would be good to go by and have the codes read. Usually auto parts stores allow borrowing their code reader, especially in the parking lot and check codes.


Good Luck

I will try and go to auto zone tomarrow and i will write back..thanks

Running rich could be a dirty injector also... leaking when started ..
I came across some text on the subject of hard to start issues that were known to be an injector problem..

A cleaning process is tremendusly successful.
For you, if it is a leaky injector a additive may help.


Good Luck

i have been doing this for my grandfather and hes been sick for the past couple weeks and hes starting to feel better so i will get back with you in the next couple days

ok went to autozone today and gave them 200.00 collateral if thats how you spell it well anyway the obd II and scanned the codes and came back as "passed" not sure what the next step should be... hope to hear back from you thanks....... ryan

Hmmm... Your computer thinks all is ok... insteresting.

Need to know if the throttle was touched when the turn off after ten minutes of running and restart normalized it.

I wish you had a tachometer.. The throttle body may be dirty.
You could try some carb and choke cleaner and spray inside the intake area and see if it clears out some debris..

I know the system will run up if the AC is on to compensate for the load but thats only during the time the pump is on.

Do you think the throttle is stuck? Or the PCM is running up the throttle?

Dont be suprised if using the car more often clears this.

Did you disconnect the battery for 10 seconds?


Hang in there..

Maybe the OP will update soon as to whether they solved their problem or not, but in the meantime here's my two cents worth.....

About 3 years ago, I had this exact same problem happen with my 95 LeSabre. I was able to trace the "fault" to a "sticking" Throttle Position Sensor. The TPS is spring loaded and under normal conditions follows the movement of the throttle. However, if it gets dirty it will stick in whatever position the throttle was last opened to, causing the engine to idle fast even though the throttle has been released back to an idle position. To solve the problem, I simply sprayed the TPS down good with WD40 while manually working it from it's minimum to maximum travel (with a paper towel crammed underneath it to absorb all the overspray and drips, of course).

As stated, this happened about 3 years ago. Since then, I've had to apply my "fix" one other time about a year ago.