QuestionI've got a '88 Buick Century with a 2.8l V6, 159,000 miles run good, starts 1st time cold or warm. After the engine warms up and I drive for a few miles, and I come to a stop (stop sign/stop light), the engine idle surges up and down and them may die. It will start right back up ok. It will also do the same thing when I pull into the drive, put it in Park...surges up/down then may die. Recently replaced 2 injectors (wouldn't start), plugs, wires, coil pack, battery. Thanks for your help. cd
AnswerHi,Chris
What may be happening is the idle air control motor is not responding or is plugged up with carbon,though this is not the only cause but its the first thing i would check,the IAC is located on top of the throttlebody its black in color and looks like a small can it has a connector with 5 wires connected and 2 screws that secure it on the the IAC housing,purchase throttlebody cleaner from the parts store like Gumout,removed the IAC make sure you save the oring,clean the IAC and the inside of the housing with the Gumout spray cleaner,wipe with a rag,reinstall the IAC,also clean the throttlebody,open the blade up and spray the throttlebody,next you need to perform an idle relearn,this is usually done with a scan tool but you can attempt it manually,first remove both battery cables,short both positive and negative cables together without connected to the battery for 10 seconds,reconnect the battery,start the vehicle,it may be hard to start due to the cleaner but restart and run until it gets to normal temp,turn off the engine for at least 20 second,then restart allow to idle then put in drive without ac or heater on and leave it idleing in drive for 1 min,after 1 min leave in drive and idle,switch the ac to on and again leave ac on in drive and idleing for 1 min,after 1 min,turn off the eng,wait at least 20 seconds,and restart the engine check that the idle is normal and no surging,let me know how it goes and contact me if this does not fix it and i will lead to further diagnosis,Thanks
ED
