[Big6ft6]

It appears that I have 4 different "fuel" lines coming out of the sending unit on my 89 burb (TBI). 2 appear to be pressurized hard lines...

1) hard line w/filter = main supply
2) soft line to rear end = rear end breather?
3) other hard line no filter = ????
4) other soft line = ????

Obviously one of the pressurized lines is the main supply (it has the fuel filter on it) one of the soft lines is a breather line coming out of the rear end pumkin.

That leaves one soft line and one hard line unaccounted for. Both run up to the engine compartment along the passenger side frame rail. What are they? One must be the return line, but which one, the hard or soft?

And if one is the return line, what is the other one?

 

[tbplus10]

One should be a vapor line running to the evap canister.

 

[Big6ft6]

One should be a vapor line running to the evap canister.

thanks TB...that must be it, the remaining soft line is the evap canister return. The remaining hardline must be the main fuel return. Not sure why the main return needs to be hard line with threaded fittings...return line should not be pressurized?

 

[tbplus10]

On an injected system the return line is still pressurized, not sure how much pressure. There isnt any pressure reducer on the return line tho.