Hi,
I am currently have issues with my car.

We changed the fuel cap seals as the old ones were worn out, then the next time I went to the petrol station, when I opened the cap it made a woosh kind of noise. I
thought nothing of it and proceeded to put fuel in and closed the cap. I then started the car and pressed the fuel tank button (To change the operating tank, the car has two). After driving for a little bit I started to smell petrol, when I got home I realised petrol was coming out behind the right hand side back wheel.

To fix this problem, we require a diagram of the fuel line in the car to figure out what has gone wrong. I have looked online and found a few although they do not contain the whole fuel line from the back tanks to the front wheel.

If anyone knows what the problem could be or has a diagram it would be greatly appreciated if you left a comment!

 

Sounds like the vent lines may be plugged - your old cap seals were allowing the pressure to escape. Try to determine where the petrol is leaking. If the tank can be pressurized it can also be imploded, ie. the tank will suck in on its outer side as fuel is drawn off and cause a split in the metal with subsequent leakage at the next fill-up.
The first illustration shows the fuel cap assembly. The little hose in the lower LH corner goes to the circuit in the second illustration. The steel line in the second illustration (listed as CAC4510) goes under the car to the carbon canister in the front RH wheel well. There is a check valve in line just before the carbon canister that is known to be problematic. The check valve is of GM manufacture if memory serves.

I'm sure others will chime in - this isn't an uncommon problem as these cars age.

 

Ditto:


Metal basher has it covered about as well as it can be done.


I did note how the "SMOG" inspector "tested' my "evap" system. Merely, visual and tactile. Opened the caps, noted the presence of the "soft" material. Depressed it and noted it was springy.


More "modern" cars use screw on caps. My Jeep failed because of a cracked cap. New cap and all was well, passed.


Carl