You did mention that the smell is strongest near the driver rear wheel when parked didn't you? Also I don't think the tests I mentioned were that complicated. Remove 3 hoses and either plug them or pressurize them using low pressure compressed air. The hardest thing is to pressurize the filler neck using a rag and the compressor nozzle with low pressure.

If you think about the smell in the rear, with the tire rotating forward under acceleration. It is easy to throw the vapors forward similar to a rain soaked tire spinning water all the way forward. The smell in the rear wheel area may not be your only problem but is A problem. And one that you should be able to find. Don't discount the gas cap or the vent either. Remember the vent acts like a check valve. And check the vapor canister for saturation.

Dave

 

As I mentioned on an earlier post, I’m having exactly the same problem my fuel pump was replaced recently and I then started getting a gas smell checked the canister and found the pipe running from the tank via the Pressure control valve had come off, so i replaced it but I’m still getting a gas smell just like pvkn1ght!

Thing is I have no way of pressurizing the system so I can perform the diagnostic procedure listed by slopokrodrigez.

I will be checking the pressure control valve on the engine as soon as I get a chance, also how do i check the condition of the canister?

any help would be appreciated.

also there are some good diagrams in the Chilton manual if that helps pvkn1ght

 

To pressurize all but the tank, you could use any source of air including blowing into the hoses. Remember these are air tubes not fuel lines. You obviously won't be able to pressurize the tank since you will need compressed air to provide the kind of volume to do so. To check the vapor canister for saturation if memory serves, you can blow into one tube and look for heavy fuel smell out the other. I have seen some that actually dripped fuel when turned upside down. But that is very rare. I'll look at the shop manual to see if I see anything else.

Oh on my procedure above, I said not to jack the car from the back. That is not correct. What I should have said was don't jack it much higher than normal height, just enough to get the left rear wheel off. With the wheel off, you can get to everything much easier.

Sorry about that
Dave

 

Ok Dave, thanks for that, I’ll try it at the weekend, also one other question the canister has 3 pipes on it one to the tank, one to the engine and the 3rd is listed as a vent do you know where the tube from that comes out? As I can see a rubber hose hanging down just behind the driver’s side rear shock, and I’m hoping it’s that other wise I have an unconnected hose!
And lastly is the vent from the tank the one connected to the round plastic thing near the rear shock?

Thanks in advance for your help

Graham.

 

The hose hanging down you are talking about should go to the center connection of the vapor canister. That's the fresh air inlet port. The tank vent you are talking about is the white plastic valve on a bracket in front of the axle. It will relieve both pressure and vacuum if it ever gets above a certain point at the tank.

Since we have already hi-jacked this guys thread enough, email me for some interesting points on the pressure control valve operation and let me know if you have a pre or post 96 vehicle.

 

that's no prob, just keep posting here, i'm reading up too.

according to the chilton's manual, there's a PCM controlled pressure valve for a quick-purge that is opened only during: 1) certain rpm's, 2) certain speeds (mph), and 3) certain engine temps. this sounds like it could be the problem since mine smells only after warm-up, when the car is moving, and when it is accelerating (rpms).

slopok, could you tell me where this pressure valve is and how i can check it's integrity?

Thanks.

btw, i also had a hanging rubber hose when i first took a look at the canister, i reconnected to the middle inlet on top of the canister.

 

Thanks for the info Dave, emailed you with my car details,

pvkn1ght once I get a chance to take a look at my car I’ll post the results

Thanks All

Graham

 

i have the same problem!!

i recently replaced my fuel sending unit and changed out the fuel pump and put in the other sendin unit and now when i get to speeds of 60+ i start to smell a gas smell!!


at 1st i thought it was cause i didnt have the carpet in the back hatch cause i took it out, cause when it rains it gets soaked sometimes and starts to smell!!

i also have the cut on top of the car to get easy acess to the fuel pump!!

but im going to check the canistor thing in a bit and let you know!!

right now im dealing with a hole in my hooker LT

 

Well after a long delay (damn job ) I’ve found my problem the gas tank is holed/split around the gas pump hole, found out when I filled her to the top and had gas dripping all over the place, (after a month long lay up due to the rotten weather up here in Vancouver, BC), so a new tank is on order should be here next week lets hope this is the end of it

 

still cant find my problem!!

 

Add me to the list. Same problem on my 95 T/A. Drive it park it and come back in 10 minutes and it REEKS of fuel. Not really raw fuel but a fuely smell. Hard to describe the smell isnt it? I only notice it after driveing and parking the car with windows up for a few minutes then going back to the car. Seems to go away after sitting a few hours. Cars put away for winter but this is one of my first projects when it comes out.

 

you might want to check your tank the place I took mine says they see quite a few split GM tanks!

 

i had the same problem after i installed a new fuel pump. it turns out, the rubber hose that connected a hard plastic line to the metal line on the top of the tank was spewing fuel. i just put hose clamps on it and it hasnt leaked since.