I have a 02 PR5, automatic transmission. It started with a rough idle and no acceleration after a hot soak. This has progressed to a hard start also and now occasionally cold. No codes, full power once it clears up. Takes about 5 to 20 seconds to clear. Well maintained, replaced the fuel filter just to see. Almost feels like the snorkle has a tear after the airflow meter but it is fine. Fuel pressure is in limits. It is starting to get regular. It has been a nightmare to get it to duplicate while testing, so I have wondered if anyone else has run into this. Also, the scan data is correct. I even scoped the TPS signal. I may have some time off at T'giving and will post some actual voltages.
Thanks
Jeff

 

I am not sure how you give the car a hot soak. Does it fit in the bath tub?

I would check the ignition system. Then I would replace all vacuum hoses, they are 10 years old now, and I would give it a "Seafoam" treatment.

 

It's the twenty minute window when the car is shut off after it has reached full operating temperature. Minimum two thermostat cycles. The engine temperature increases during this time after it is shut off.
Ended up being the VICS valve for the tumble chamber. Eventually set a code. Back to over 40MPG on the highway : )