Ey legends, twice in 6 months my carby has blocked up with a decent amount of soft light grey stuff almost like a type of sealant. I cleaned out the fuel tank and new fuel sender and itnhas been fine for about 6 months and now that same grey stuff is back. Motor is a new 350 chev only about 7 months old with a mechanical fuel pump is there any sealant that goes on them when mounting to the motor? Any other ideas?
If there is any plastic fish tank style "fuel" line in the system it will dissolve in the gas and be deposited in the carb throat as fuel evaporates.
If your tank has been treated with that POR15 type stuff, could be some of that stuff coming loose and getting into the system. That stuff is grey, from memory.
The bloke who owned this car before me did some dodgy shit hence the new motor so that is probably something worth looking into
I used KC cleaner the tank came up like new, the grey stuff was coming through before the tank was cleaned also
Do you have an effective inline filter ? If the tank isnt made of unobtainium , you may be better off replacing it . A canister filter like a frame hpg 1 is effective.
I just have a filter between the mechanical pump and the carburettor which caught alot of the grey stuff i mentioned
If the filter is catching grey stuff, that suggests to me that the source is either the filter itself or something before the filter ... eg tank or lines up to the filter. You say you cleaned the tank and it came out "like new" ... are you absolutely certain that what you were looking at (inside the tank) was raw steel and you weren't actually looking at some sort of sealer from previous owner and that sealer is now slowly breaking down? That being said, do you have a locking gas cap? Any chance someone (maybe a neighbor) doesn't like you and is occasionally pouring crap of some sort into your tank?
Put 2 filters in parallel, not in series, ahead of the fuel pump, and one filter after the pump. Change them every 6 months.
We tipped out the tank once properly cleaned and it was only rust. Definitely not a neighbour as my car is locked away in the shed. Is there anything inside a new mechanical pump that it could be coming from?
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