tank vent

[DocGraphics]

I have my 78 back on the road & she is a wonder to drive!
90* out, not a cloud in the sky just criusing down the highway, Ahhhhhhhhhhhh

Question is that I seem to building up quite a vacuum in the tank. When I open the cap it sucks air in hard.
I'm having problems w/ it starting when hot & wonder if the vacuum building up is causing that.

How is it suppose to vent?
Could I drill a vent hole in the cap?

Now that I'm back on the road I imagine I will be having quite a few questions as problems crop up.

[jfrawley]

I have an '82 FI Spider and try as I might, I just couldn't solve that issue. I changed out all the hoses and valves on the fuel retrun lines but still couldn't get it to work correctly. I ended up drilling a very small hole in the gas cap and never had an issue again. Not sure it's the right way, but it sure works!

John

[maytag]

I have an '82 FI Spider and try as I might, I just couldn't solve that issue. I changed out all the hoses and valves on the fuel retrun lines but still couldn't get it to work correctly. I ended up drilling a very small hole in the gas cap and never had an issue again. Not sure it's the right way, but it sure works!

John

how old are you?
I only ask, 'cuz us old guys used to do that to our gas caps on every car we owned! Especially here in the mountains where drastic altitude changes in short periods adds to the problem.

[jfrawley]

I'm 61 and learned that trick many years ago. Funny thing is, it really works.

John

[DocGraphics]

Thanks for the input guys, sounds like I'll start with drilling the cap for the venting issue.

One other thing I already found is I had changed the fuel filter to one of the clear plastic ones & when hot it got softer & kind "creaky" when I flexed it so it might have had a crack in it.
I put the old metal one back on & things are a little better, still have to crank a bit when hot but not as much & it hasn't died again from what seems like lack of fuel when idleing HOT (happened 2 times w/ plastic filter in 1 day & none w/ metal ever)