Volvo 340 starts to shock

[MasterD]

Hi,

I bought a 22.5 year old Volvo 340 GL. It is working fine, most of the time.

However, sometimes the volvo 340 starts to shock, like not enough gas is supplied. In low gears even the engine shuts off when in this 'shocking mode'. It can take hundreds of kilometers of driving before the shocking stops again. Letting the engine cool off or warm up has no significant effect. It starts to happen when the motor is either cool or warm and it can also stop when the motor is either warm or cool. It happens in both warm weather and in cool weather. It usually starts to happen when driving in slow traffic or when accelerating fast and I believe it can be stopped by controlling the gas pedal really consciously and careful. If the car is in shocking mode the only way of driving is when choking, especially in low gears.

The gas pump has been changed. The carburator has been checked. What else could it be?

[Jos360]

Carburator can be "bent" by the heat of the exhaust running under it. If you put a new, or refurbished carburator on it, it should be good. This also caused my 340 to blow out the gaskets.

[MasterD]

Ok, thanks, sounds like a possible explanation.

However, if, the carburator is 'bent', what does allow it to be bend back?

Letting it cool off doesn't fix the problem.

It appears to be fixed rather randomly, however, treating the gas pedal gently, I believe, has a positive effect.

[Jos360]

If the carburator is bent, it happens on the surface where the petrol goes in the intake manifold through the nozzle. With a file (that is the English word i think?) you can make it horizontal. You have to replace all of the gaskets offcourse.

If you open the carburator and you see that de gasket around the nozzle is screwed up, then i think this is the solution.