Poor Running (intermittent)

[Charles Farran]

Hi Iain,

If the rev counter is stable when you have intermittent running are you sure you haven't still got any fuel related issues?
Are the carb pistons nice & clean & haven't got waxed up with old fuel , with the car having stood since the summer. Has the in line fuel filter got gummed up ? Is the small hose connecting the two carbs in good condition & not collapsing / bit of rubber breaking off internally? (I have had all these over the years).
Is the fuel pump providing fuel at about a pint every half minute?

Cheers,

Charles

[MGB72]

Thanks Charles, this is where I'll be starting.

"small tube connecting the carbs" - what do you mean, I don' think I have one (HS4)

[Ian F]

Good point Charles. I'm afraid I was misled by the description of the tachometer as being "static". I misunderstood and assumed it meant reading zero.

Ian F

[Ian F]

P.s.
My '72 BGT doesn't have such a tube as far as I can recall - I can go and look if required!!

Ian F

[MGB72]

I was going too but it's raining...

[Charles Farran]

Apologies Iain,
My 1980 car has HIF carbs which has a small hose connecting the front carb to the rear carb that is hidden behind the air filters. Never the less worth checking that the internals of your fuel hoses aren't breaking down as modern fuels attack old rubber....
Worth checking that the carbs fixing nuts to the manifold are tight & that there are no air gaps.
Cheers , Charles

[Vic Butler]

Charles, from memory only HIF carburettors have that pipe.