2.2 OBD2 swap into ‘85 Brat

[el_freddo]

Not having a charcoal canister with the purge control still in use makes sense. 

From what I understand of this setup is the charcoal canister collects vapour from the fuel tank vent system which is then burnt off in the cylinders when the ECU determines the right conditions are present - usually a cruise and light load revs. 

No charcoal canister means no vapours which is effectively just sucking air and leaning out the fuel mixture. Add in a faulty valve that could be open all the time and you get your stumbling revs/misfire like running symptoms.