blackozvet

try the locking nut and let us know if it makes any difference,
if it doesnt i will deny ever having suggested it !

Lemme

I took the bolt out and put a nut on. I screwed the bolt in as far as I could and it had only a marginal improvement in the pressure. Lucky if I got 40 psi at idle. The rapid pulsing of the fuel pressure gauge needle is still present and is a worry. The fuel pressure gauge drops to zero only 15 minutes after engine turn off.

I am putting my money on the pump being past its use by date. I rechecked for leaks at the fuel tank and it is dry. The pump is in transit and is currently in Alaska ready for the big journey down under.

383vett

I wouldn't worry about a fuel pump that bleeds down after 15 minutes. I've got a pump that bleeds down in 20 seconds after shutdown but it puts out plenty of fuel to not go lean at wot. Good ol LM-1. However, you are going lean at wot so you probably need a new pump.

Lemme

What about the pulsing of the needle on the pressure gauge. Doesn't seem right.

blackozvet

In Alaska ? is it getting the cryo treatment ??
another captain obvious question, what shape is the diaphram in inside the regulator ?

Lemme

Apparently it has just left Hong Kong.

Circular shape I presume? Have to take it apart to find out I suppose.

blackozvet

when i said shape i meant condition ?
is it the original diaphram ? a bad one can do similiar things like letting pressure bleed out etc.

Lemme

It came with the superram/accel intake which is secondhand but it was working OK before the pressure started dropping recently. If the new fuel pump doesn't fix the problem I will have a closer look at it.

383vett

Has the gauge always pulsed or is it a recent thing? Maybe the gauge is too sensitive and doesn't have any dampening built into it. I've got a 10 year old gauge mounted on the rail and it's as steady as a rock.

Lemme

It is a recent thing. I was half wondering whether the gauge is faulty. It is not oil filled as good ones are.

383vett

Probably the gauge.

Lemme

I have a new oil filled one on order.

Fuel pump is now in Singapore.