hi guys.
my iroc has a strong fuel odor in the rear. so i think there must be some leaking hose or something but i cant find anything. could someone show me a fuel lines diagram please? (from the gas tank to the engine)
thanks

 

There is a rubber coupler between the fuel filler neck and the tank itself. VERY VERY common for it to dryrot and crack and leak in these cars. So common that i got $1 down that's it.

Just get under the car and check it out.

 

Never seen any rubber hose on the filler neck.

I know that sometimes the vent valves go bad, they are hidden under the car next to the fuel tank on the driver side. Could be that too.

 

Wasn't there a tank recall for the neck cracking on some years?

 

OK, whatever, maybe it isn't rubber, i know they do crack and crack often, lol. So sue me, been 8 years since i read the FAQ that talks about it.

 

Yea, IIRC it was 91 or 92, or both. The rest of us... take a hike. Not that it couldnt happen, but you know how it works.

 

I remember a 3/8" hose coming from the fuel sending unit within a few inches of the fuel tank with what looks like a check valve at the end. That might be stuck open and giving you oders.

 

Possibly a cracked filler tube to tank soldering joint, mine had it too. Especially when filling it all the way up the smell was really bad. Fuel simply leaked past the cracked seam. I think this comes from people leaning on the pump nozzle when filling up.

Here's what mine looked like, the wet stain is gas


fixed


there's no rubber on the tank anywhere, all hard lines


The rubber is on the end of the lines, a screwed one w/ o rings for pressure, then a return and a vapor line as well as one going to the pressure release valve, the white thing:

 

I have the same issue with my newly purchased 89 IROC 350 TPI. After driving the car and parking- I get a strong smell of gas fumes from the rear of the car. Seems to be coming from the drivers side rear wheel well.

The car has an after market locking gas cap...most likely non vented.
Couple of tests and observations:

1. The tank does have considerable pressure when I smell the fumes. If I open the gas cap I get a large pressure release.
2. While under pressure I pulled the fuel eval line from the characoal canister under the hood. No pressure released. A very minute gas smell, but no vent or pressure release. I even pulled the check valve and rubber line all the way back to the metal line that is fastened to the frame.
3. I do suspect that my smell is coming from the white check valve vent line from the tank that is mounted near the drivers side wheel well.

Is my vent line going to the front of the car clogged somehow?
Should I blow compressed air from the front of the evap line back towards the tank?
Everyone says vented gas cap- but why is pressure not being released via the evap line/characoal can?

other thoughts?

thanks!
Jason

 

Sounds like the vent is stuck closed. Its the white piece clipped to the brake bracket in Twin's pic

Common replacement from Dorman at any local parts store

The sucking sound is the gas tank expanding. When fuel is pumped out of the sealed tank, its volume is replaced by negatively pressurized air (vacuum). The vent is supposed to allow a controlled amount of air into the system overtime so this doesnt happen

 

thanks for the reply- but I am 90% sure I have positive pressure in the tank, not negative (vac). When I release the gas cap I get a rush of air around threads of the cap, and a VERY strong smell of gas for a few seconds.

Besides- if I did have vacuum in the tank (neg- pressure) why would I have the gas smell? You'd think that would not happen with air trying to get in the tank.