1966 Volvo 121

[quietside]

Could be wear to the spindle(s); after being open at full or at least partial throttle one or both plates are failing to close- probably the primary, leading to a weak mix and stalling.

The carburettor is less than six months old and has fewer than than 1000 miles on it.

I wondered if some kind of pressure difference was buggering around with the plates inside the carb.

I've got a line on a NOS Zenith 36VN - OEM fitment - to try just as an outlier.
The original fell to pieces after being ultrasonically cleaned.

[quietside]

Could it be weak idle mix , then drawing in oil on the overrun , valve guide seals worn,( high vacuum ) , which puts out the fire in the cylinders ? Does it smoke when at the bottom of a hill you apply the throttle ?
Petrol tank vent partly blocked ?

No smoke under any load.

Petrol tank was another suspect of mine.

[christine]

I was thinking about Miss Shillings orifice . Did someone already suggest fuel surge in the carb under braking . How about raising the float bowl level a bit . It must be infuriating !

[Nibblet]

Could be wear to the spindle(s); after being open at full or at least partial throttle one or both plates are failing to close- probably the primary, leading to a weak mix and stalling.

The carburettor is less than six months old and has fewer than than 1000 miles on it.

I wondered if some kind of pressure difference was buggering around with the plates inside the carb.

I've got a line on a NOS Zenith 36VN - OEM fitment - to try just as an outlier.
The original fell to pieces after being ultrasonically cleaned.

No, not in this instance; Spanish Weber carbs are shite, though frankly many Italian Webers are shite, I take it that the springs are snapping the venturi closed as they should? The springs can be quite feeble, barely enough to overcome all the friction of a more complex linkage.
At any rate you've got either a fuel starvation problem an air leak or an especially evil intermittent electrical fault- possibly where an ignition component is shorting under braking- is anything live able to short to earth if swung about?

[red5]

Good afternoon,

may I make a couple of suggestions?

1 - check the fuel filter direction - it looks backwards to me.
2 - replace fuel hose
3 - remove filter and run vehicle
4 - wrap some tinfoil round that fuel hose - extened it slightly if possible as well.Looks too close to top hose

Thanks,
Sam

[Scruffy Bodger]

Any progress with this?

[quietside]

Any progress with this?

Fixed, finally.

One of the lives wasn't connected to the car at all.



There's a plate on the starter that the lives connect to via a ring connector secured by a nut.

It *looked* like it was connected, but it was just roughly terminated and pushed together with a bit of tape.

It had been off for so long it was covered in verdigris. I had an alternator fitted but it wasn't charging; then, both lives snapped off the ring connector (probably owing to their tenuous connection and extra voltage) and the car stopped dead on the A55.

That's when we realised that the second live hadn't been connected for some time (and the other cable was barely connected).

The wiring to the ignition switch is also a mess and the switch itself is tired. I think someone had tried to fit some accessories near the switch (or hotwire it) but bodged it back up when attempts failed. It needs a new switch but payroll is taking the piss at the moment.

Eight fucking years this thing has played up. It's been taking the piss longer than it's behaved.

[Eddie Honda]

Electrical gremlins. PITFA.

[quietside]

Electrical gremlins. PITFA.

Especially when it doesn't behave like leccy gremlins and the fucking car starts and runs!

AAAAAAAAAAAAAARGH.

[Hooli]

Nice find & welcome back. Have you been dead for tax purposes?