Hey all, wonder if you can help me - hopefully I have this in the correct section, its fuel based question but its very much specific to this engine/carb setup i think.
My 81 has the original 200ci inline six that was in it when it was imported from the USA in 1981, with the original carb, Holley 1946 model I believe.
This is a model that would have had the mechanical fuel pump on the side of the engine (opposite side the inlet/exhaust) that pulled fuel from the tank up to the carb which seems to have a one way valve operated by the float.
There is no intank pump, and the only other line that comes from the tank seems to be a vapour line that goes into a t-piece, joining vapour from the carburetor that then goes down to the charcoal canister.
Now, before I bought the car somebody obviously had issues with the mechanical pump (parts are not as easy to find in this country!) and replaced it with a little universal electric pump which did the job ok for a year or so, unless it got really warm. To fix the heating issue i relocated it from the engine bay to the rear of the vehicle next to the tank and replaced it with a slightly more expensive universal pump. Unfortunately that one died, as did another Facet cube pump which according to the write ups are supposed to be pretty reliable. The cheap one that the previous owner had put on works still in this position but it leaks and doesn't hold good pressure. When i replace it with a new one the pressure is constant and it runs great for a few days then the pump dies.
So I'm stuck trying to find a new universal 12v electric pump, but they all seem to show diagrams with a return line. The way I see it, when the carb bowl is full it shuts off the one way valve and the fuel becomes solid behind it, which could then kill the pump. But there is no return line fitted on this vehicle and nothing I can see on the carb that would allow me to fit one short of building a regulator system just before it and plumbing a line back to the tank along the whole underside of the car. It seems like the car has never had this and wasn't designed to have this in it (until the later EFI models I assume?).
I'm sure someone else on here may have run their inline six 200s with the original carb but an electric pump - have you managed to find a pump that will survive dead-heading, or have a built in regulator of some sort? Or have you all fitted regulators at the carb and a return line? Or am I missing something and the carb I have does have a return line function (maybe using the vapor line that goes to the charcoal canister?)?
Any help would be much appreciated, the car is basically off the road until I sort this! Shame it runs fantastically when it has a good fuel supply, just can't seem to find a reliable pump!
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