Fuel tank outlet

[Tundra]

Spent the morning trying to solve fuel starvation. Worked back from the carb and eventually seem to have narrowed it down to the fuel pickup pipe.if I put the flexible into a fuel can everything pumps/flows well.
On my tank the pickup looks to be held into the tank by a union type fitting - does this ring true with anyone else and should I be safe undoing it without anything dropping off the other side into the tank so I can check for blockage?
Doing all this with the boot outside in fresh air and plenty of breaks to let fumes disperse.
Trying not to think about a new tank.

[wilf]

I have taken that union apart without any problems - it is just a compression joint around the suction tube, which runs down to close to the bottom of the tank.

[Tundra]

Thanks Will, confirms what I just found after getting brave. Next hiccup is you can’t fully withdraw the pickup with the tank in place so looking for some thick wire to give it a rodding to see if it changes anything.

[wilf]

A gentle blow through should tell you if it is blocked.

Just a thought - I too removed that pipe (just undo the tank fasteners and "turn" it a touch to get it fully out) when I was chasing a fuel starvation issue which showed up at wide throttle openings. That turned out to be the seals etc.inside my relatively new SU pump having been badly affected by ethanol - a rebuild kit sorted it. The pump was still working, but it's output was well down in terms of flow - the book figure is 140 pints per hour at a three foot head, or just over a pint in thirty seconds, which you can easily check. While I was in there, I fitted a fuel filter (same type as in the engine bay) on the suction side of the pump to protect it from any debris in the tank.

[Tundra]

Satisfied myself no blockage in the pickup and nowhere along the pipe so most likely culprit has to be a tired pump. Got a £10 cheapo from Amazon on the way to prove a point before getting more technical.
Always have fitted filters before the pump which wasn’t looking bad which is why I was beginning to suspect the pickup as a possibility. Years back I had a 3 litre Capri that drove me mad with fuel starvation that would go away after the car had been stopped for a while. Turned out to be a blocked filter on the outlet pipe inside the tank. It was blocked solid but the body had cracked which allowed fuel to flow around the filter until you had a heavy foot and then it sucked the joint closed!

[jbuckl]

Satisfied myself no blockage in the pickup and nowhere along the pipe so most likely culprit has to be a tired pump. Got a £10 cheapo from Amazon on the way to prove a point before getting more technical.
Always have fitted filters before the pump which wasn’t looking bad which is why I was beginning to suspect the pickup as a possibility. Years back I had a 3 litre Capri that drove me mad with fuel starvation that would go away after the car had been stopped for a while. Turned out to be a blocked filter on the outlet pipe inside the tank. It was blocked solid but the body had cracked which allowed fuel to flow around the filter until you had a heavy foot and then it sucked the joint closed!

Interesting.

Recently heard of a stag running issue solved:-
The steel front to rear fuel pipe was blocked!
I had measured the delivery to be ok.

best to replace it with nylon….. some stags didn’t have a steel front to rear pipe anyway. Some were originally nylon.