Raw gas fumes in 71z

[DC871F]

Been around Z's a while and know most usual suspects in gas fume and exhaust issues with these cars, but......

Series 1 car, I have dropped tank, replaced all vent lines with no kinks, pressure checked expansion tank on right side, checked for fuel leaks front to back.

The issue is raw gas fumes present in garage when car sits overnight, and sometimes driving with certain combinations of window configurations (drivers window down and passenger window cracked).

Checked filler tube seal, filler tube vent line to expansion tank, replace PCV valve, all lines to flow valve guide are good.

No exhaust fumes at all, just raw gas.

The car has after market Webers with the little rectangle air cleaners, this is the only thing I can think of that may be the issue because the stock air cleaner isn't on the car.

Any thoughts?

[AK260]

I used to get that. It was a number of things like the usual suspects - jubilee clips not tight enough, old cracked breather hoses etc.

BUT, the one that REALLY eluded me was the tank fuel level sensor - it has two pins coming out of the back: one is ground and welded on, the other has a black plastic insulator. The metal around the insulator had rusted and there was the world’s tiniest weep coming from it! And I mean it looked like a tiny old damp oil mark.




Once I replaced the sender, no more fuel smells of that magnitude ever again.

But I do love opening the garage door and getting that smell of oil, fuel (evaporated from carbs) and vinyl mixed together - takes me back to being a kid in the 70s!!!

Good luck buddy.


EDIT: just realised you are using DCOEs - so all bets are off :D !! I’ve never had them but read many a post that speaks about them spitting back fuel through the intake etc.

[DC871F]

8 hours ago, AK260 said:

I used to get that. It was a number of things like the usual suspects - jubilee clips not tight enough, old cracked breather hoses etc.

BUT, the one that REALLY eluded me was the tank fuel level sensor - it has two pins coming out of the back: one is ground and welded on, the other has a black plastic insulator. The metal around the insulator had rusted and there was the world’s tiniest weep coming from it! And I mean it looked like a tiny old damp oil mark.




Once I replaced the sender, no more fuel smells of that magnitude ever again.

But I do love opening the garage door and getting that smell of oil, fuel (evaporated from carbs) and vinyl mixed together - takes me back to being a kid in the 70s!!!

Good luck buddy.


EDIT: just realised you are using DCOEs - so all bets are off 😄 !! I’ve never had them but read many a post that speaks about them spitting back fuel through the intake etc.

Replace the sender gasket while the tank was down, and the sender is still shiny with no corrosion.

Looking at your pic of the seep at the sender makes me think I have some kind of seep somewhere lime that I'm chasing. 

I'm going to install the SUs and all the original stuff. PO put the webers on.

[Richie G]

I'm not knowledgeable enough to help out here (yet!), still dealing with changing out my own vent hoses.  Did want to comment on one thing though, I too will miss that mix of vinyl and vapor smells when I'm done lol.  My 5 year old and I open the car door and stick our heads in to catch a whiff every now and then.

[Jarvo2]

I've been using a lot of seam sealer from underneith while my trans & diff are out.  I can't believe how many cracks there are between the sheet metal and everywhere else.

[Richie G]

One thing I can comment on the POR patch product is amazing. Might be a good option for you. While I've been dealing with the exhaust hoses I've been dealing with surface rust under the old sound deadening and in the spare tire well. Grinding out that rust made a few pee and dime-sized holes the POR patch did a great job super easy to use rock hard and now I'm taking the POR paint and doing the entire deck area before laying down new sound deadening.

[emccallum]

1 hour ago, Jarvo2 said:

I've been using a lot of seam sealer from underneith while my trans & diff are out.  I can't believe how many cracks there are between the sheet metal and everywhere else.

 

Same here, I have tried to seal up everything during my restoration.