3rd the verify and confirm everything is everything
Per the 1981 emissions 2F red FSM
I always start at the first system circuit page section 3-4 PCv valve
then on to 3-6 fuel evap control
and this is where verifiable tech should be applied to confirm you have a sound and one way only vented inward airflow
Working propped gas cap ....
old rusty ones with a bad gasket or stuck closed check valve or safety valve as it is termed
like so :
Per the 1981 emissions 2F red FSM
I always start at the first system circuit page section 3-4 PCv valve
then on to 3-6 fuel evap control
and this is where verifiable tech should be applied to confirm you have a sound and one way only vented inward airflow
Working propped gas cap ....
old rusty ones with a bad gasket or stuck closed check valve or safety valve as it is termed
like so :