fuel smell

[etuke]

I just bought a 2004 Silverado with a 4.8,its an extended cab 4x4.It had the vent solenoid code in it when I checked,i found the one of the fuel lines had rusted off right by the braided flex up by the front of the drivers door(not the main line).I put a piece of rubber over the line and clamped it tight but now notice a fuel smell from the truck.I can't find any leaks in the main line,truck runs fine.It doesn't smell all the time,and while under the truck replacing u joints for the front shaft I turned the key to the on position to release the 4x4 and instantly smelled the fuel smell.Its seems to be more towards the back of the truck.Other day I had the window down and really smelled it in the cab,brought it home to check the lines and no leaks but the next time I went out no smell.I didn't notice any smell when the line was broken only after I fixed it.reset the code and it comes back after awhile.Any suggestions on where to look?Seems to be more noticeable between the drivers side cab and box gap,i haven't had the tank above 3/4 since I bought it.

[MikeD268]

Pure guess but if you're throwing evap codes AND getting a strong smell of gas right at the driver's side cab/bed junction, I'm going to guess that the evap vent solenoid is gone. The canister lives right at the juncture. I fought this one for a loong time before realizing that, at some point after I replaced the canister and updated the breather hose location, the hose itself somehow kinked. Double check that the hose itself is run correctly and then check the breather to see if a.) it's clogged with dirt, etc. and b.) if it's been relocated per whatever dealer update covered this. May be worth it to pick up either an aftermarket OBDII code reader that plays with a smart phone or a low end actual code reader. The under-$100 investment will pay for itself in sanity and convenience in short order.

[j cAT]

GM used very poor quality steel tubing. the ethanol eats thru these steel lines in many cases from the inside out creating tiny holes that weep.

a very good spot to look is in and around the charcoal canister area. this is where the fuel lines from tank connect to the steel lines that run forward. this is were the ethanol eats at the steel low spot.. engine must be running to check for leaks !!

[MikeD268]

I KNEW you'd have a better answer than me, J C

[etuke]

thanks for the replies but when you say steel lines on the tank I thought the lines were plastic in that area.I see steel along the chassis but plastic to the tank,are you saying there are more steel lines on top of the tank?

[j cAT]

Originally Posted by etuke

thanks for the replies but when you say steel lines on the tank I thought the lines were plastic in that area.I see steel along the chassis but plastic to the tank,are you saying there are more steel lines on top of the tank?

like I said the fuel lines from the tank connect to the steel lines next to the canister. that is where they usually leak.

nylon lines are the tank lines.............THE BODY lines are steel............

so with the engine running what did you find ? you have a good powerful light ?

the other smell issue maybe the canister is with a CRACK !...so drop that out and inspect it.

[etuke]

Its hard to tell with the lines as the truck has been oiled and everything looks wet.I didn't get in there too far yet to inspect properly as today I had to replace the lower column bearing and had to remove the linkage to the steering box,when I put it all back the wheel must have turned half a turn and I managed to bust the airbag coil ribbon cable.That took me most of the day to find and fix,I didn't know they had that kind of setup in there.Guess you live and learn,managed to trim down the ribbon cable and solder it back to the connector and behold its back working again.Drove it for the first few miles with my thumbs outside the wheel just incase the bag went off.When I get a good day im going to crawl up under it and try to find the leak,its not hard on fuel so I don't think its raw fuel leak,im guessing vapor as it has the vent code in it also.

[etuke]

fuel pump was the problem,damn thing fell to pieces when I tried to remove it from the rust.