My 99 Suburban has an issue at start up. When starting, it has a low idle and without giving it a little gas it will die. Seems that after it warms up it gets better and runs normal. If I turn the motor off after its warmed up it will sometimes resort back to a rough start and sometimes not. I do not have a check engine light on. Not sure what the issue might be especially since sometimes it will correct its self after warm. A couple of my thoughts are fuel filter, throttle body needs to be cleaned, or distributer. Any other ideas? Its a 99 Burb, 5.7 liter, 4x4.