General Fuel filter full?
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General Fuel filter full?
SDHXIII
Member
I'm no expert. When my 650 engined FIAT 500 F is running, the filter doesn't fill up, simply flows through and runs alright.
Stu
Stu
This seems to be a prevalent question in the forum. Long story short, it never completely fills up and air bubbles are normal. Problems are elsewhere!
Yes, fuel fills the supply pipe by siphonage. As long as the connections are airtight and conditions are not so hot that the fuel "cavitates" with vapour bubbles, this pipe and a filter before the pump will always be full. The needle-valve inside the carburettor is moderating the output of the pump so that a filter after the pump may not always be full. If you were able to see the filter when driving at high speed or climbing a steep hill the filter might be more full.
As none of this matters unless the car is running badly in a way that relates to fuel starvation I would not be concerned. Alternatively you could replace with a metal filter canister, tape it over or simply remove it.
El cargador
Member
Hi. Mine does exactly the same but runs fine
When I push the throttle linkage on the engine......revving it...I can see air bubbles going up the fuel line AFTER the pump.......
Is this a problem?
Once in a while, the car seems to stall........by pushing the speeder pedal quickly, this can be avoided.
Most of the time it idles nicely........once in a while it conks....
I have recon’ed the carb.....and yes, it did the above before the recon....and still does it after the recon. The recon job was easy. I have no leaks anywhere now.
I think the fuel system is sucking in air somewhere......will check the lines again..
Is this a problem?
Once in a while, the car seems to stall........by pushing the speeder pedal quickly, this can be avoided.
Most of the time it idles nicely........once in a while it conks....
I have recon’ed the carb.....and yes, it did the above before the recon....and still does it after the recon. The recon job was easy. I have no leaks anywhere now.
I think the fuel system is sucking in air somewhere......will check the lines again..
Hi,
You should not see bubbles after the fuel pump. An in-line filter may not be full of fuel but there should not be s stream of bubbles through it or the pipe work. There is possible air leak on the suction side. This could be pipework or in the pump. You can sometime see bubbles before the pump as the low pressure can cause the volatile parts of the fuel to vaporise. The higher pressure at the outlet should cause them to re-condense.
Back on the clear filter bubble, this can be bleed out by holding the filter vertically with the engine running.
Robert G8RPI.
