Re: Carb Heat for Sierra.
Posted: Sun 23 Jun, 2019 12:22 pm
I doubt there is much heat transfer from the head to the fuel via the fuel pump.
It's not the temperature of the fuel thats the problem, it's the temperature of the inlet air as it mixes with the fuel - this is freezing the water vapour in the air. The atomised fuel along with the pressure drop across the venturi (vacuum) is chilling the air.
I think the last carburettor car for sale in Australia was a mitsubishi triton or similar, probably late 1990's. No, fuel hasn't changed since the introduction of unleaded in 1986, unless you're using E10 as this will exacerbate the problem as the ethanol is hygroscopic.
Just to be clear, are you still picking up your inlet air from the back corner of the engine bay between the battery and the guard?
I didn't think there was cold weather petrol, only diesel, but I could be wrong - this is because diesel waxes at very low temperatures, not a problem with petrol.
I know you've done quite a lot of work to your carb, are you still running stock jet sizes? Are you still running a stock thermostat and is the engine getting up to temperature when the ambient is low? If the engine is running cold, the carby will be too.
It's not the temperature of the fuel thats the problem, it's the temperature of the inlet air as it mixes with the fuel - this is freezing the water vapour in the air. The atomised fuel along with the pressure drop across the venturi (vacuum) is chilling the air.
I think the last carburettor car for sale in Australia was a mitsubishi triton or similar, probably late 1990's. No, fuel hasn't changed since the introduction of unleaded in 1986, unless you're using E10 as this will exacerbate the problem as the ethanol is hygroscopic.
Just to be clear, are you still picking up your inlet air from the back corner of the engine bay between the battery and the guard?
I didn't think there was cold weather petrol, only diesel, but I could be wrong - this is because diesel waxes at very low temperatures, not a problem with petrol.
I know you've done quite a lot of work to your carb, are you still running stock jet sizes? Are you still running a stock thermostat and is the engine getting up to temperature when the ambient is low? If the engine is running cold, the carby will be too.