1999 Tahoe, 5.7 Vortech V8, 125,000 miles After replacing my Idle Air Control valve, fuel filter and installing a brand new battery, I have encountered a new problem. Prior to these replacements, my engine had a tendency to idle rough and to sputter, or misfire I suppose, especially when under load, i.e., with the a/c on or accelerating up a steep hill. Now, however, the engine seems to idle high when in drive and/or reverse and has begun to completely shut off when I shift into park! I can say for a fact that I know I have at least one bad plug wire and have every intention of replacing them all once I have another free day to do so. Would this cause the misfiring and/or the stalling? Also, if it helps, the, altenator, ignition coil and fuel pump are less than a year old. I appreciate any responses and thank you for your help in advance. - Tony
Engine Stalling When Shifted To Park on 1999 Chevrolet Tahoe
by Anthony Hebert in Oklahoma City, OK on May 06, 2009
ANSWER by Russ on May 08, 2009
It sounds like the new idle air control valve will need to "relearn" its idle position. The combination of replacing the valve and the battery at the same may have made the erratic idle more sever than if only one or the other was replaced. You could try cleaning the throttle body around the throttle blade area - this will help get the "base" idle back near spec and help the new idle air valve find it correct position. You will need some gloves, a shop towel, and brake clean for the cleaning procedure. Just spray some brake clean onto your shop towel, open the throttle butterfly by hand and clean the area where the butterfly closes in the throttle bore. Wipe the area several times until most of the black residue has been cleaned away. Get those plug wire replaced as soon as you can to correct that misfire. Driving while the engine is misfiring can damage the catalytic converter.