stumble when first start driving cold

2002 XG350L with 42,000 miles has stumble when first strarting driving. Car starts fine, revs up, idle drops down then I put it in gear to drive. Car starts to bog as if it is going to die then takes
off. This is every day lately. Once warmed up runs fine.
I have tried a bottle of CHevron's Techron but did not help.
Any ideas HyundaiTech?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Dunno. If you've got a check engine lamp, you should start there.
But I'm presuming you don't. Try reinitializing the throttle: Turn the key on (don't start the car) and back off immediately and wait ten seconds. Your throttle will do a sweep.
Also do an idle learn. Start the car with the a/c on and let it reach operating temperature. Let it run for 10 more minutes. Then turn the a/c off and let it run for another ten minutes.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
hyundaitech wrote:

Is there any indication that the throttle sweep has been completed? Is there a beep or any dashboard light indication?
Matt
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Unfortunately, no. The only way you'd know for certain is to have someone listen or watch under the hood while you try to make it happen.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Idle learn? Never heard of that. I did try the sweep but it didn't help. With the idle learn I just leave it idling the whole time?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Yep, just leave it idling. It'll watch and learn where it needs to leave the throttle plate for proper idle rpm.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Is it safe to clean the throttle plate with cleaner? Engine running or not?
I know a lot of cars can be harmed if this is not done properly (ruin O2 sensors, remove coatings, set trouble codes, etc).
Also, thanks for all the assistance on here. Your feedback and advice is invaluable!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
It's okay to clean the throttle plate with carb cleaner (while not running).
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.