what does the evac do on my car, or what does it have to do with the fuel pump, the connections to fuel pump are tight.
Do you mean ‘evap’ as in fuel evaporation vapor recovery system?
YES
It prevents the fuel vapors from going back into the air. You get a little cleaner air and a little better mileage as you get to burn it.
It is also the reason you likely have a sticker on your car telling you not to top off the tank when you fill it. If you do you can damage that system and then you may have a very difficult time filling your tank. It also likely will not pass EPA inspection.
What is the year, mileage, and engine of your Eldo?
What are the symptoms?
Under what conditions do they occur?
What are the codes (if it’s 1996 or newer)?
We’d like to help, but without any information we cannot.
We could describe an EVAP system…the vent lines, the activated charcoal bed, the purge solenoid, the purge valve…even what “activated charcoal” means…but I doubt if that will do you any good.