Does anyone know the name or function of this black cylinder located on the fuel return line ?

Does this cylinder run off of vacuum ?

No guesses please, if you dont know, dont answer.[IMG]

 

That's the EVAP solenoid relay. The PCM closes it to purge the EVAP canister where gas vapors are collected from the gas tank. The vapors are drawn via vacuum into the intake manifold to be burned in the cc.

 

So, does this engine have a return line ? That was one of only two lines that I have going to the gas tank, and the other line has a fuel pump on it !



OK so what you are telling me is that this line should be mounted HIGH in the fuel tank if I were using a fuel cell ? If it were mounted on the bottom, it would suck in gas ?!? and probably flood the engine ? Maybe ?

 

Yes. My C5 has a line that goes back to the EVAP canister which is next to one of the two gas tanks. The EVAP canister is filled with activated charcoal and stores the vapor until the PCM purges it. The f-body canister is attached to the top of the gas tank. If you'd like an iillustration, email me at edbon@adelphia.net.

 

Well, all my engine has is what looks like two lines used for fuel ? Your engine has 3 lines ?

 

There are two lines. The illustration below from the 2002 f-body manual shows line 3 as the fuel line and 4 as the EVAP line.

 

So there is no fuel return line then ! ? The way that you are talking, both lines go INTO the engine ! I thought there was a return line !

 

its a returnless system the fuel pressure is regulated with the fuel pump. GM went to this system on the newer model trucks.

 

The 97-98 C5's had dual fuel lines with a supply/return setup. The manuals I have show that the 98 f-body did not. If you look at a 97-98 C5 fuel rail, you'll see two ports where as the f-body manual only shows one. Later C5's converted over to the single fuel rail line - my '02 is like that.