Fuel Starvation?

[RCHunt]

My 142 Rally car has been running well for a time now and I'm generally very pleased with how it goes.
However something occurred the other day which I thought had been solved. The car has twin HS6 SU carbs and Facet electric fuel pumps. I stopped on a hill to allow traffic coming the other way and the car would not pull away. The revs just died as soon as the clutch was released. Eventually I was able to stagger away and the car picked up once on the move.
This seems odd since it cannot be the first time I've stopped on a hill! It certainly has always climbed hills perfectly happily before although I did have a similar thing happen some while ago but I have stripped the carbs and replaced the floats, needle jet etc. since them.
I suspect something is sticking and causing fuel starvation, maybe being on a hill is part of the problem. Any ideas?

[Clan]

Originally Posted by RCHunt

My 142 Rally car has been running well for a time now and I'm generally very pleased with how it goes.
However something occurred the other day which I thought had been solved. The car has twin HS6 SU carbs and Facet electric fuel pumps. I stopped on a hill to allow traffic coming the other way and the car would not pull away. The revs just died as soon as the clutch was released. Eventually I was able to stagger away and the car picked up once on the move.
This seems odd since it cannot be the first time I've stopped on a hill! It certainly has always climbed hills perfectly happily before although I did have a similar thing happen some while ago but I have stripped the carbs and replaced the floats, needle jet etc. since them.
I suspect something is sticking and causing fuel starvation, maybe being on a hill is part of the problem. Any ideas?

Facet Fuel pumps are NOT reliable they have a rated life of just 3000 hours which is ( 3 1/2 years for me, not good enough.) and on the data sheet it says under no circumstances to be used for aircraft engines. I have had 3 pack up on me, all failed on the motorway, 2 of the cube types and one cylindrical pump. The cylindrical one caught fire and burned through the casing ! However it hard to find any other electric fuel pump which can flow a decent supply for a large engine. So I have fitted 2 in parallel with a selector switch on the dash for WHEN one of them fails next.

I have just looked everywhere for the data sheet which stated the rated life which used to be published freely by the sellers ( Merlin motorsport) but can find no trace of it now, I can see why !

[RCHunt]

Interesting. The car has twin pumps mounted in parallel. I've only used one pump for a while as I suspect the other may be suspect.

[142 Guy]

How steep was the hill? The design of the early 140 gas tank is less than stellar and on my 1971 fuel injection tank the fuel pick up is not in the lowest part of the tank. The last 3 - 4 liters of fuel is never recoverable and on rough roads my fuel pump will suck air if the tank level is running near the bottom. If your fuel level was running towards the bottom 1/4 of the tank and you were heading up on a reasonably steep hill the pump might have been sucking air.

I think the later 140 with the forward mounted tank did not suffer from this problem.

[RCHunt]

I thought about that but the car actually has a replacement tank fitted behind the rear bulkhead, to lift it up from potential damage in the standard position. It was actually virtually full and the hill not particularly steep.