my fuel pump does not prime when i put the key in and turn the ignition to on. when i crank the engine over it primes, but it takes a while to start because the of the priming of the pump. what should i look at to see why it is priming in the on possition.

thanks eric

 

944 fuel pumps only run when the engine is being cranked and when the engine speed is above 400 rpm. Part of the electronic injection logic. If you are having to crank the engine over for more than ten seconds your fuel line check valve is leaking or your fuel pressure regulator is bad and not building pressure in the manifold. Could also have leaking injectors into the engine or at their connection at the fuel rail. Fuel on the engine is very bad.

Fuel line check valve is at the output of the fuel pump.

Always post the year and model of your 944. Keeps us from over guessing.

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