1988 Buick Regal idle

I've been go'n thru the same problem for 2 months. Under the dash by the drivers right knee is the Diagnostic Connection. Take a 3" piece of wire & stripe about 1/4" of the insulation off both ends. You'll see 2 terminals in the upper right corner of the Diagnostic Connection side by side. Put one end of the wire in 1 terminal & the the other end of the wire in the other terminal. Turn the key to the ON position, it should be 2 clicks. DO NOT START THE ENGINE with that wire in the terminals. You'll hear the fan turn on & the 'Service Engine Soon' light with come on. Count the blinks on the light, it will blnk once, pause then blink twice. That means is a code 12 which tells you it's running the diagnostic test. It will flash code 12 three times then it will blink the 'Trouble Codes' stored in the computer in the same way it blinked code 12. When it's flashed all the trouble codes you have it will flash the code 12 again to let you know it's done. Make sure you take that wire out when you take the key ouT. You can find the 'OBD1 Trouble code Chart' here or at FreeAutoMechanic. Com. & Look up you codes to see what the problem with your car is. To clear the codes from the computer, just disconnect the positive battery terminal for 30 seconds. Hope this helps you!