Houghton

iTrader: (1)

Seen posts about the pressure/vacuum issue when removing the fuel filler cap and I always concurred with the general feel that it was a negative pressure.

Well today, in this heat, it was definitely pressure, as I released the cap seal, I could see vapour, or rather the distorting effects of it. Quickly put my hand to the bottom edge of the cap and could feel it blowing out.

The usual hissing noise went on for much longer than usual and was more pronounced, more pressure than normal

No carbon canister fitted BTW.

Gerry

911

Agree!
I have now piped my return pipe from by the fuel filter down to the back of the gearbox using screen washer piping about a month ago.
All is well, no fuel probs and no hissing thus the pump must be 'happier'!

No carbon canister either.

Regards,
Graham.

Houghton

iTrader: (1)

What return pipe is that Graham? I won't begin to ask if it's the fuel return

Should that be 'the return from the carbon canister'?

When I took the CC out I just yanked on what I thought was a vent pipe, seemed to disappear through the inner wing, low down. Instead it was one side of a tee, which broke. There's another pipe that went to the valve under the inlet manifold, (can't remember what that's called but that's now gone too)

Remaining pipes are both open ended but pressure is still present in tank.

I'd have thought that positive pressure would assist the pump, whereas vacuum would be counter productive, causing the pump to work harder.

I'm even more confused now

Gerry

Houghton

iTrader: (1)

Sorry Graham, just read your post properly The pipe was 'by' the filter

Gerry

911

I think you are with me now Gerry, you are cleaverer than me as you have a 2.5 Sti v3......
Graham

Houghton

iTrader: (1)

Odd measure of clever Graham I have a 3.3L V6 Chrysler too so that makes me super clever

I'll have to take a proper look at what's left in the way of tank breathers or maybe leave the filler cap loose