Vacuum buildup in fuel tank

[davidball]

Just got back from a long drive during which the car experienced fuel starvation. Fuel pump and filter were ok but when I removed the fuel filler cap there was an inrush of air. The car drove ok for about another 40 kilometers then the same happend again. Anyone know where the fuel tank vents on an 1987 super sprint?

[NuisanceFactor]

Probably through the filler cap. Which filler cap does your car have? The 'Aero' style ones came with and without vents.

[davidball]

I do not know. I did have a problem getting the cap off when I fueled up this morning. I will take it off and look for a vent hole.

Edited by davidball on Sunday 22 November 07:27

[Epimetheus]

If you have a breather it may be blocked somehow (e.g. someone may have cable tied it up too tight).
If this is not the case, you could drill a very small hole, maybe 2mm, in the filler cap. I had to do this on one of my cars when I fitted an aero-style filler cap. I didn't realise you got vented and unvented ones.

[pacman1]

Epimetheus said:

...you could drill a very small hole, maybe 2mm, in the filler cap. I had to do this on one of my cars when I fitted an aero-style filler cap. I didn't realise you got vented and unvented ones.

Exactly my experience many moons ago with a Sherpa van fitted with a replacement, unvented cap.

Edited by pacman1 on Sunday 22 November 09:21

[davidball]

The filler is an Aero type. The cap has a red plastic fitting at the end. From searching the web I am led to believe that a red end means the cap is not vented. Vented caps have a green end. Is this a sort of standard? If I drill a hole in the cap will it require a valve?

Edited by davidball on Monday 23 November 09:30

[Epimetheus]

Just drill a tiny hole under the flap - it'll be fine

[davidball]

Thanks

[Irish]

I had exactly the same issue. 7-indulgence fitted a nifty tank breather.

Got the car back today. WOW - just goes to show what a professional set up can do.