1992 Buick Lesabre

Engine Performance problem
1992 Buick Lesabre 6 cyl Front Wheel Drive Automatic 188000 miles

As of 4-26-08 my buick has had a lower than normal idle and now I have to slightly press the gas pedal down to start it.
Within the last month, I have replaced the sparkplugs and wires, the trans fluid and filter, engine oil and filter, and fuel line. {Within the last 3 years, the radiator, the heater core, the fuel filter, the tires, alternator, new battery, and a new timing gear set}
It had been running normal until the low idle. With the low idle the engine does seem to run just a very small amount warmer.
(might this be related to the summer blend of fuel in California?) Any ideas would be appreciated, Thank-you.

April 29, 2008.

Cross these two terminals as shown, then turn the key on. Count the flashes, a 22 will flash as 2 flashes then a short pause, then 2 flashes, if more than one code is stored, the pause will be longer. The codes will display three times and end with 12. Write them down and post here. This connector is right under the middle of the dash...Let me know what you find, I think it will be either a bad ECT or TPS...

Apr 29, 2008.
Do you have a check engine light and when was the last major tune-up?

Inspect and test the idle air control valve and throttle position sensor.

Apr 29, 2008.
The " check engine light" has not come on yet for this issue. As for a tune up, the car hasnt had one for the last 4 years. Although, it ran fine until two days ago.

I will inspect the idle air control valve and throttle position sensor, but for testing those, would I need a scan tool and/or a voltmeter?

Apr 30, 2008.
Forget about testing anything until you do a complete tune up! Four years?

Apr 30, 2008.