I ran a search and didnt find a real definitive or informative issue. Any HR owners run in to the issue that when warm starting, the idle plummits to around 200-300 before catching its self and bouncing back up? the car borderline stalls when it happens. Doesnt occur during cold start. speculation is carbon buildup on the TB's?
any advice appreciated

 

Mine does that sometimes. I don't think its a big deal. Just everything stabilizing.

 

How many miles on the odo?

 

bought it at 60k and did it from day one. just over 100 now

 

Sounds like you need to do an idle air relearn, it should fix your problems. One important piece of information though do you have stock intakes or some aftermarket kit?

If that doesn't fix it you can try to clean the throttle bodies and than do an idle air relearn.

WARNING DO NOT TOUCH YOUR THROTTLE BODIES WITHOUT FIRST DISCONNECTING THE BATTERY, DISCHARGING THE SYSTEM, AND THEN DISCONNECTING THE THROTTLE BODIES. You can then clean them with a lint free towel but do not spray the throttle body cleaner directly on the throttle body spray it on the towel! I was fine with moving the throttle plates, some people will tell you not to do it, but do it gently and do not let them close harshly or force them all the way open.

NOT FOLLOWING THESE STEPS CAN AND HAS LEAD TO DEAD THROTTLE BODIES AND FRIED ECUs.

Cleaning you throttle bodies is a touchy subject on this forum with most people saying you shouldn't do it as it has ended up in multiple deaths of throttle bodies and ECUs. The process above worked for me but I am not responsible if you break parts of your car.