As most know, there's not much that adheres to the black poly plastic fuel tanks. The only thing I could find that might work is 3M DP8005, which is what I put down around the vents prior to coating with clear silicone. It's a 2-part epoxy that requires precise 10:1 mix, so I also had to get the gun, mixing nozzles, and plunger specific to 10:1. I've spent about $90 so far. A new tank was around $500 and then I'd have to move over my pump and hoses. Found a junk yard tank 100 miles away for about what I've spent on the glue.

3M DP8005 epoxy
FYI, the epoxy comes in black and white. I chose black. I put a bead around each vent. The epoxy bead really crinkled up as it cured. I think this epoxy is meant more for an adhesive smashed between two plastic surfaces rather than a seam sealer, so that's why I added silicone...to fill and smooth it out. The silicone probably won't help much.

 

Plumber's GOOP sticks to darn near everything I know it sticks to HDPE where RTV won't. They also have a marine grade.

Have you even considered the flex pipe on the exhaust? I suggest that because of the absence of any drips and evidently stronger than a vapor leak (that would throw a code).

I would replace the EVAP vent valve if it was full of dust.

 

I'm not sure of the flex pipe, although I see no evidence of fuel dripping. There's not much of the fuel smell under the hood anywhere, that's why it's so strange. I cannot pinpoint a source.

My tank appears sealed up now. I can tip it on its side and no gas wetting around the vents!

I got the tank back in and all hooked up. It starts and runs ok. No immediate smell but I need to fill the tank and drive it a little. If the smell goes away I'll blame it on either the evap solenoid being cleaned out, or the leaking vents that are now sealed. If the smell returns I'll take a closer look at the evap system and check out that solenoid better. Does anyone thunk an evap canister can wear out?

 

The flex pipe is part of the exhaust, between the header and the #1 Cat. They crack, causing exhaust odor to get into the cabin while also telling the computer to add fuel to the A/F (fuel odor).

 

Filled the gas tank and drove around, about 20 miles. Smell is gone as far as I can tell. Maybe some slight residual smell from before. My wife says it's nothing like it was. I'll claim tentative success.

Crawled under to check out the exhaust flex connector. There is no obvious crack, fuel or exhaust staining etc. I should've fired it up to check for any exhaust leak but did not. With my washboard road I wouldn't be surprised to have an invisible crack.

Now on to investigate the possible stretched timing chain causing CEL. Currently has code P0010. I've changed solenoids before but the problem seems to keep returning.

 

It might not be the solenoids, but the wires.

https://www.obd-codes.com/p0010

 

Are you changing the oil regularly?

 

Thanks for the link. It did give some useful explanation. We do have packrats and squirels that damage vehicle wiring here so I'm always on the lookout for signs of chewed wires. Everything looks good around the solenoid connectors and wiring as far as I can follow back.

Honestly I don't understand the function of the two cam shaft position solenoids. Do they control the flow of oil to trim timing?

 

I change it based on the oil life % given on the car's information readout and try to get it done when it drops to 25%. Admittedly not the best at maintenance.

I've read that oil cleanliness affects the solenoid valves.

 

Yes the solenoids control the camshaft actuators or phasers to adjust timing accordingly, dirty oil can cause problems.