4.3L TKS running issue

[roadnoise]

I have a 2012 MerCruiser 4.3L TKS engine. Symptom is: the engine starts right up after "normal" cranking. Left to idle, it runs fine for a minute or so, then dies. Rinse repeat. Interestingly it dies after almost exactly the same amount of time. It does this regardless of whether the engine is warm or cold. If I start it up, put it in gear and accelerate, it dies sooner. It acts as if there is a certain amount of fuel available after starting and then dies after using it up. Just had it in the shop for these symptoms and the mechanic cleaned the carb and informed me it "ran great". Ideas?

 

[alldodge]

My guess without knowing more its your Oil pressure switch
Crank the motor and power goes to fuel pump and fills carb. Motor is running and key is released so now "IF" the oil pressure sensor re-powers the FP then it continues to run. The oil pressure switch is not making contact so it runs out of gas

 

[roadnoise]

My guess without knowing more its your Oil pressure switch
Crank the motor and power goes to fuel pump and fills carb. Motor is running and key is released so now "IF" the oil pressure sensor re-powers the FP then it continues to run. The oil pressure switch is not making contact so it runs out of gas

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First off, thank you, thank you, THANK YOU!

This was exactly the problem. It was easy enough to test the switch--the engine started up and the switch never closed. Ordered a replacement on Amazon, installed it, and it runs like new. I think this switch has been flakey for some time before it finally died completely, now that I know the symptoms.

Thanks so much for the response and for the diagram. Really helpful.