Fuel Pressure

[djj_engineer]

Tried to find out why my fuel pressure gauge falls to zero.
The car will run but not flat out. It seemed to object to climbing Rest & be Thankful in 4th and wasn't happy outrunning cars form our local traffic lights!
So far i have removed and rebuilt the fuel pump and got fuel to the engine the pressure regulator seems ok. Tomorrow I shall removed the Dash to have a look at the gauge!
I thought I had got over the fuel starvation thing.

[b_caswell]

Re: Fuel Pressure

A mate of mine(I do have a couple) had problems of fuel starvation when the car was pulling hard. It turned out to be the pickup in the tank was very close to the bottom of the tank and it was pulling the tank bottom up and resticting the fuel supply.

[milliemarlin]

Re: Fuel Pressure

A couple of things to consider:
Is the fuel pump actually powerful enough?
Could it be overheating?
Millie had huge problems with the fuel pickup, even at slow speed, until I added a sump. You mentioned acceleration; could the pickup be too near the front of the tank?
You have a fuel pressure gauge; does the pressure drop gradually as you speed up or suddenly drop at speed?
Can you give us any measurements to build up a picture of the problem?
Paul

[dogoncrazy]

Re: Fuel Pressure

Derek
Have you checked float chamber valves - my roadster experienced similar problem once , caused by tiny piece of rubber hose coming adrift and partially blocking float valve. Engine would run fine until high demand called then would lose power. Float chamber couldn't fill fast enough due to restriction.

[djj_engineer]

Re: Fuel Pressure

Thanks for all your thoughts.
It seemed to be a lack of electrical power to the pump.
there seemed to be a resistance at the fuse box and the Alternator, although, providing enough power to give some charge would not run the 4 front lights and the fan. The the fuel pressure dropped to zero ( it is a mechanical gauge so it cannot be affected by any electrical change)
I now have a replacement alternator ( although I had to resort to the gas axe and a no 7 tip to remove the pulley nut!!!) I have just got it off so will try fitting the lot this afternoon.