Fuel starvation - I think..........

Woke up early Saturday to go to work and having set off in the Landy I noticed that if the throttle was partially depressed it was fine however, if I fully depressed the throttle the engine lacked all power and wanted to die.

Thinking possibly a blocked fuel filter I replaced with new but still faced the same problem and symptoms. Thinking bad fuel drained tank and replaced fuel but in doing so I noticed a lot of pressure in the fuel tank to the extent that the cap wanted to pop off once unlocked and the fuel spurted out of the filler pipe.

Then I decided to leave the fuel cap off to see if that would improve things but it didn't. Then thinking that possible air had got into the system I decided to bleed the filter housing again with the lift pump but I couldn't for the life of me get it to bleed any fuel from the top of the filter housing even after pumping for well over 10 mins and yes the lift pump was on cam and resistance was felt in the lever.

I'm really confused

Why does the tank build pressure???

Why does the lift pump now not bleed the filter housing???

And why is the Landy not running properly???

Well managed to sort it this morning.

Having spoken to a specialist I changed the fuel cap - blocked breather attributing to the pressure problem in the tank.

Changed the lift pump and replaced fuel filter.

Job done runs perfectly and revs freely with no power loss.

Happy again.

Lift pumps are good for around 100k, as you have just found out.

brit part lift pumps aren't good for 1k miles

Ya did well to sort it easily, those probs can be a nightmare to nail down

Mechanical Lift pumps need to be off cam to pump, so next time you check one, crank the starter and turn the engine over a fraction then retry the manual priming lever. Every apprentice gets caught out by this. I had it on my trade test in the army, they had cut off the lever inside the pump, but it would prime ok, engine would start and then die. By putting your thumb over the inlet and pumping it, the suction should hold until you remove your thumb and on some a light click can be heard.