Gas Fumes - LS Swap in a '86 K5 Blazer...

[PWagon]

I did an engine swap a few years back by putting a 5.3 LS in my '86 K5. I've noticed that on warm days I smell gas fumes coming from the engine compartment. I can't deal with this anymore, and I have to fix it. I've tried tinkering with the vent canister, but I guess I don't know how to vent its fumes into the 5.3. The engine did originally have an EGR equivalent (valve on the top/front of intake near the throttle body), but I don't have the electric plug or circuit anymore after the engine swap (and don't plan on adding it back). So, I have to come up with something creative. Has anyone else run into this scenario? I don't see any hose fittings on the intake manifold to vent my fumes into. If I added one to my air cleaner box, would the gas fumes change/alter my mass air flow sensor readings? I could use some suggestions here.

 

[K85 Octane]

ditch the canister and put a vented gas cap
that's what my 68 is but then again the tank filler is in the bed

 

[paratrooper307]

I've hear of people running a line to the intake before the MAF. Typically evap setups have a solenoid or control valve that allows the canister to purge vapors into the throttle body/intake, but it shouldn't be absolutely necessary. Most people that do LS swaps on older (non-emissions) vehicles and want to vent the tank usually grab a canister setup off of a newer vehicle.