Engine cut out

[les g Swaffer]

Would the engine cut out if the wire to the sensor on the carb broke
as that is all I can see wrong atm

[Steve940estate]

Is the wire to a sensor or is it a fuel cut of valve of some sort ? I know some cars have them fitted but haven't got any experience of carburetted Volvos.

[OldBlueVolvo]

Hi, is this the 1986 740GL? If the carburettor looks like the one in my project thread then it has a vacuum operated fuel cut off valve. The only electrics are for the hot-start valve and choke heater.
However, it sounds like you might have a Weber DMTR carburettor like the one in the photo below. Yes? There is a blue wire rising up through the the inlet manifold on these cars, which is the 12V electrical feed for the carb. On Weber carbs that wire connects to the fuel cut off valve, so the car wouldn't idle if it is broken. It would however still run if you keep the revs up or keep the choke on.

[les g Swaffer]

Originally Posted by OldBlueVolvo

Hi, is this the 1986 740GL? If the carburettor looks like the one in my project thread then it has a vacuum operated fuel cut off valve. The only electrics are for the hot-start valve and choke heater.
However, it sounds like you might have a Weber DMTR carburettor like the one in the photo below. Yes? There is a blue wire rising up through the the inlet manifold on these cars, which is the 12V electrical feed for the carb. On Weber carbs that wire connects to the fuel cut off valve, so the car wouldn't idle if it is broken. It would however still run if you keep the revs up or keep the choke on.

No Its anot a webber carb not sure the make something like petenburg this thing controls the emisions
Have a look tomorrow as the cars stuck around the corner .
thank you

[OldBlueVolvo]

Is it one of these bad boys - the Pierburg 2B5?

[les g Swaffer]

Originally Posted by OldBlueVolvo

Is it one of these bad boys - the Pierburg 2B5?

That looks like it the thing I am on about sits where I've put here has all the pipes that go to the top of the carb.
carb2.JPG

[OldBlueVolvo]

Is the problem that the car conked out and now won't start?

Or that the engine cut-out once but is OK now?

[les g Swaffer]

I conked out
I had cleaned the carb out and put it back on tried it around the block
went perfect as it had been not accelarating properly then I stopped to let a car through accelated and all the power went.
tried everything I could think of and flatend the battery

[OldBlueVolvo]

Of course you'll need that battery charged back up.


Just a few things to try...

• Does the tach needle move when cranking the engine?
• Sparks at the plugs?
• Will she start and run with the accelerator pedal pressed half way, or even fully pressed?
• Check fuses (esp. 10 & 13).
• Can you see fuel inside the fuel filter?
• Are the jets clear? Esp. the idle jet.
• Pull off the connector from the switchover valve on the left suspension turret and check that there is 12V across the two terminals when the ignition key is on position II.
• Mend the damaged wire.

I'll see if I can think of anything else.

[les g Swaffer]

Thanks it maybe the fuses as I tried to wind down the window so I could turn the key and see what as happening from outside and the did not work
Thought that might be due to low battery
let you know
Thanks again