Rough idle when hot

My 92 GS 3.8 runs great with 3 exceptions. After a long drive, if you shut the car down then start it up while still hot, it idles erratically, high and low. When I first pull away, it hesitates in the lower rpm range 2000 or less. Also, when pulling a hill or needing power at about 1500rpm (ie-hwy cruising), it hesitates and I have to shift to third to overcomne the problem. All 3 issues are somewhat intermittent. I'm new to this post and appreciate the help. The car has 180,000 miles on the original motor, still looks and drives great. Passed an emissions test with no problems a month ago. Thanks all!

I think you might have a dirty fuel filter. I would try changing this first. A new filter costs around $6 and it's easy to install. If it's never changed and it has 180K miles on it then it's long overdue for one anyways.

Hi,
Also have the TPS (throttle position sensor) checked. These can be checked with an ohm meter by a mechanic.