1987 Buick LeSabre is idling too fast

Have u checked ur air filter. Check it. Turn ur car on and listen any hissing sound. If u do hear somthing find the noise and fix or replace the hose. Its called an air valve leak. I used to have a 1994 buick lesaber and i had the same problem. Let me know if it worked or not. Thank you.

Buick LeSabre Questions - Running without a Mass Air Flow ...

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CarGurusJun 11, 2013 - It drives perfect then all of a sudden while im driving it stallsoccasionally. ... it idles ruff an stalls until it warms up does the same in gear its throwing engine ... If you are installing a idle air control valve in a 1990 Buick Centuryyou ... I put in my 3rd MAF sensor in 2 weeks and now the car is no longer stalling.

vacuum hose to vent door could be off or busted, problem in climate control. replace idle air control valve to bring in down

There is no idle adjustment on a 1996 Buick LeSabre. The idle speed is computer-controlled. Incorrect idle speed can be caused by many things including a faulty Idle AIr Control (IAC) motor, vacuum leaks, or malfunctioning sensor inputs or circuits such as the Throttle Position Sensor (TPS). If it is not idling correctly, the engine control system must be properly diagnosed to find out the reason why.

Under the hood of your Buick, find the Air Filter canister...follow the large hose to the top of your motor...at the injection end you should see the accelerator linkage...have someone rev your motor while you are looking for the movement of this linkage...at the bottom of the cable connection you will find a small threaded insert...by turning this insert clockwise, you can see the insert is shorter...this lowers the idle...Normally this is pre-set...and many variables can cause a fast idle...if your computer is working...the idle may reset while you continue to driv...Hope this helps...

Change your Thottle positioning Sensor. My 93 lesabre did the same thing and i changed the TPS and it stopped.

check your idle air control valve(IAC) its probably dirty and are not able to move freely
the IAC valve controls the air mixture at idol speeds

The coolant temp sensor sends signal to the ECU and the ECU adjusts the idle RPM. When the coolant is cold, the engine requires more fuel to sustain idle with thick oil (oil gets thicker & more viscous when cold). This makes the engine to idle at faster RPM but it should settle down to 850 RPM or so after the coolant warms up. The sensor is nothing but a thermistor; a device that changes electrical resistance according to the coolant temperature.

did you clean the idle speed control air bypass valve?, u do this by spraying carb spray into the intake while the engine is held at hi idle so it won't stall, use up about half the can, then shut down and disconnect battery for 5 minutes to reset system idle learn, drive the car for a few days and let me know if the problem is fixed.

Bad transmission, plugs, fuel pumps. That is all I think will definately give u such results.

Rate please.