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G'day all
Another ecu conversion project , this time with a Pajero, injectorless.(4 stages )
First stage is with a d1927a, and controlling the fuel cutoff solenoid in the minuki to stop deiseling, but also activated during high map and low TPS under a certain rev range for deceleration enleanment. (And just maybe depending on if it works, as a duty cycle wideband 02 cruise fuel adjustment akin to closed loop)a
As I'll be running a mechanical pump for stage 1 and 2, Im unsure if I need to retain A FORM of the oil pressure fuel pump cutoff. If I did, it would be in the form of a fuel cutoff solenoid between the pump and carby, wired in thru the oil pressure switch.
Knowing the setup is generally only for electric pumps that would runon when the car is wheels up,and that most carby setups in an accident stall, and wont operate when upside down, kinda duplicating the effect of the oil pressure switch .
My question is, will the fuel tank drain thru a carby when the car is upside down?
This is the only edge case I can think of for using a switch off solenoid, can someone tell me if a carby , upside down will drain a fuel tank?

The floats would be hanging fully shut upside down so can't really leak

Unless of course they are blown open by pressure ... Won't take much.

-Enjoy
: )_~

The general rule of thumb is that the tank itself shouldn't be able to drain if upside down - this is achieved by running your vent lines so that they go up above the tank, but actually terminate at a height at or below the bottom of it (in a loop). Or alternatively if this isn't possible of you're expecting higher risk (motorsport) you can get rollover valves which shut off automatically.

About the only shut off solenoids I can think of in a carb application is the idle stop (which blocks the idle air passage) that is there to avoid run-on.

Also if you're talking about the oil pressure switch on a VN Commodore for example its not really a cut-off, its a second circuit that's there for limp home mode to actually keep the pump running (albeit reasonably safe since it won't keep running after the engine stops).

Thx gents, some quality replies, there.