[mr-pitts]

Absolutly nothing to do with your car Gary, but a few years ago when I was flying Pitts Specials there was an American Pitts pilot who had to make a forced landing due to a engine stoppage in flight.It turned out to be a problem with the fuel system,further investigation revealed a Frog in his fuel tank(and yes it was dead).It was worked out that the only time there was any chance of getting anything in the tank was when refueling.There was alwayys somebody present when this took place,for obvious reasons.

It turns out and although it couldnt be proved,that the poor Frog must have found its way into the fuel tank whilst it was being made.Although I dont remember the exact figures the Aeroplane was a few years old with quite a few hundred hours on it....How on earth did it manage so long without a problem?


Soooooo! check you aint got any Frogs (dead or otherwise)residing in your tank This story is completly true.

[GaryB]

Well I filled up at an Esso station recently when I couldn't find a Shell station so there could well be a tiger in there...

(Apologies to any younger readers who may not have the slightest clue what I'm on about).

[richmc]

GaryB, on 23 February 2012 - 03:34 AM, said:

Well I filled up at an Esso station recently when I couldn't find a Shell station so there could well be a tiger in there...

(Apologies to any younger readers who may not have the slightest clue what I'm on about).

And just remember "The ESSO sign means happy motoring", but not at these prices.

[GaryB]

So to summarise what I have learned from this thread so far;

1: It could be water in the tank
2: I can't be ar5ed to remove the tank.
3: Wynns dry fuel could help
4: My head is too big
5: If you a fly a stunt plane, beware of frogs.
6: I'm old.
7: So is Richmc.


You just couldn't buy this kind of education.

[GaryB]

And so you recognise me on Friday MrP...

[richmc]

GaryB, on 23 February 2012 - 06:42 AM, said:

And so you recognise me on Friday MrP...

That picture is priceless, I love your expression, and you missus will kill you when she finds out you've used her wok as a toilet.

[mr-pitts]

GaryB, on 23 February 2012 - 06:36 AM, said:

So to summarise what I have learned from this thread so far;

1: It could be water in the tank
2: I can't be ar5ed to remove the tank.
3: Wynns dry fuel could help
4: My head is too big
5: If you a fly a stunt plane, beware of frogs.
6: I'm old.
7: So is Richmc.


You just couldn't buy this kind of education.

There is no chance I can get my head between the seats,

I think that just about sums it up.

[F3 ANG]

brilliant, I've just had a sh*t day at work, you've cheered my day up no end

[GaryB]

We should go out on the pull together MrP. The chicks would stand a chance..

[Ultra_Nexus]

It's not water in the tank BTW.

Water is heavier than petrol and the fuel pickup is at the bottom. Regardless of fuel level, you'd be getting water.

It isn't the filter (sock) per say. Having seen them on Hondas approaching 20 years old, they remain in good nick

The fuel pump pickup actually sits in a pressed out lowpoint that only holds a couple of litres. If the so called sh1t in the tank even existed, 10 litres of fuel would be surplus so that the sh1t would still float above the pickup.

If the sh1t was heavier and sank to the bottom...well, happen at any level. What i'm trying to say here is that it isn't sh1t in the tank

So what could it be?

Personally, I think that you might be getting air into the system. Either that or your fuel pump is going and that the extra pressure of a full tank is masking the pressure loss.

Basically, you are going to have to remove the pump.

[GaryB]

Filled up this morning on one of my twice weekly fuel stops and noticed that when I open the filler cap, it sounds like I'm opening a can of pop. Fsssssssssssssssssssssssssssssssssssssssssssssssssssss.


Now I assume from this that I may have a blocked breather pipe which may be creating a vacuum in the tank thus causing the pump to struggle?

Possible or am I just coming up with wild theories to explain the cause?


I guess I could run it low again this week, try opening and re-seating the filler cap and keep driving to see if that makes it any better.

[richmc]

When you get to around 20L open the cap to release the vacume and see if you still get the 10L problem that would prove what you just posted.

Edit, I always get a fizz when I open the cap, but how much is hard to say.

[Turtle]

The evaporative emissions system (charcoal cannister etc) will allow some fuel tank vaccum. You could check the plumbing, but without watching the valve signals during a driving cycle it's hard to be sure.

If the fuel tank vacuum does get too high you will have fuel starvation type symptoms, up to and including miss firing. Seen that on a car that had the evaporative emissions system removed, but a problem with the vent valve fitted in it's place.

Simple test. Run the fuel level down until you hit problems. Stop and remove the fuel filler cap. That will put the tank to atmospheric pressure. Replace the filler cap and drive off. If the problem goes away for a little while after releasing the fuel tank vacuum then the problem is likely to be in the evaporative emissions side of things. be sure to just remove and refit the cap though - don't add any fuel or you won't be testing if it is excessive tank vacuum.

-Brian.