Fuel pressure?
 

I have a problem with my 1800s. The carbs are not shutting off the fuel and are putting huge amounts of overflowing petrol into the airbox, stalling the car and making it dangerous and undriveable. I have changed the needle valves for new grose jets, which did not help, then back to new standard needle valves, no difference again.
The fuel pump is standard and with spacer. When I remove the fuel line to the carbs the pressure is excessive, and I can't understand why, any ideas? I'm just about to swap out the pump for the one on my amazon, which has an identical set up but not this issue.

Any thoughts on why I might have this excess pressure gratefully received, thanks,

Dave

Some QH (Quinton Hazell) pumps for the B18/20 were known to give about 4.5psi which is too high. You only need about 2.5psi. Doing the Amazon swap is a good idea.

You could also try adding an extra, thinner spacer to the existing fuel pump which would reduce the pressure to the carbs. This might be advantageous if you want to keep driving your Amazon too. :thumbs_up:

Thanks. I swapped pumps over, and in the process noticed that the fuel line from pump to carbs was rather tightly clamped (by me..cough) up by the top rad hose. That small extra compression was lifting the pressure at the carbs enough to overcome the floats. All seems well now, which is good news. Simple things these cars, and the same can be said for myself.