The dashpot is adjusted by loosening the locknut on the body and then rotating the dashpot in or out. The car should run at about 1800 RPM when the dashpot is extended and drop back to idle in about 5 seconds after you release the dashpot pressure. A recent smog test for several MR2s. These cars were completely stock except for the HKS pully and had a new no-name brand catalyst installed on the SC car. The legality of some of these items is highly questionable and is presented for informational purpouses only.
User assumes all risk and liability.
So, you've done all of the above and the car still won't pass. Methanol and Ethanol both mix with gas and burn much cleaner. Some rubber components may be destroyed by them, so extended use is not recommended. Run the fuel tank down to almost empty. Add 1 or 2 gallons of Ethanol or Methanol.