When I start the car in the morning it starts without issues at a cold idle of about 1200 RPM. I then drive about 3 blocks and turn off the car before it has had a chance to fully warm up. About 5 minutes later, I get back into the car and start it up. Upon start up the car idles at about 200 RPM and when I put it in gear and the car just dies. If I sit and wait with the car at 2000 RPM for about 2 minutes the idle is great and has no issues. I have also tried another method. I work the brake and the gas until I get onto a straight away and then I hit the gas. After I am on the gas for a few minutes the idle issue goes away. I have also checked all vacuum lines and I can't find a leak.
What could be causeing the car to idle at 200 RPM after I have started the car and drove it for 3 blocks turned it off and then restarted the car?
The car also hesitates from full stop idle to full throttle and at about 3000 RPM the car finally comes alive. If I hit the gas on the freeway there is no hesitation just a hesitation from full stop idle to about 3000 RPM. During the hesitation there is a very low deep sound coming from the engine and when it reaches about 3000 RPM the deep sound goes away along with the hesitation.
I looked at the Idle Air Control (IAC) and experimented a little with it. As I started the car up it idled fine and then I drove around the block and shut off the car. I then started the car back up and the car would idle at about 200 RPM. I disconnected the IAC and the RPMs shot up to 1500RPM. I plugged the IAC back in and the idle went back down to 200 RPM. I then put the RPMs at 2000 and let the car warm up to operating temp. I put my fingers over the port for the IAC in the throttle body and the car died.
Could my issue be the IAC is bad?
Also, a few months ago I checked the codes in the computer and I had a code for an O2 sensor before the catylitic converter. The code stated the the O2 sensor was slow to respond.
Would a bad O2 sensor only affect the idle when the car is cold or would the O2 sensor cause issues when the car is either hot or cold? Would an O2 sensor cause hesitation from full stop idle to about 3000 RPM?
Please help me resolve my idle issues. Thank you in advance.
Edited by Snowboarder, 19 February 2012 - 07:42 PM.














