I have a 81 vw caddy which my dad bought new. I have had it restored to near perfect condition. I still have two issues that have proven to be difficult. First a machanic thought he was raising the idle and he changed the air adjustment screw on the intake. My gas mileage had dropped tremendouly. I have been all over try to see if someone has an oxygen sensor which would allow us to set it. No luck so I have been experimenting with the screw. Any suggestions. Second I have notice the truck having increasing difficulty starting in warm and hot situations especially if if had been driven and set for 5 or more minutes. It seems to be flooding by bleeding by injectors. Problem is the injectors are new and only have about 500 miles on them. What I have noticed is a gas smell coming from the vehicle if driven agressively. When I take the gas cap off it appears to have a lot of pressure buildup. Could there be a problem where pressure buildup in tank is opening injectors even when the truck is shut off thereby flooding the truck. It seems to help if the gas cap is left loose.