lift pump squeak

[Scott]

cpl 1975 2100 hours, twins. Starboard engine getting harder to start- last summer changed the last chance filter and had a hard time priming. Mickey moused a bulb setup to get it fired and then replaced it with a SMX double double. Put 700 nm on the pair of engines with no problem.

6 months later I have the same problem getting it started. the double double is full of fuel but the lift pump cannot produce a squeak, just a buzzing sound. The double double can produce the same sound without the lift pump.

Is the buzzing sound air or is the lift pump and/or check valve shot?

Topic

[Tony Athens]

Bosch Lift Pump

The “spring” inside the pump can “break”.. Also, the “return check valve” can also break to where it will not hold proper pressure..

I’d start with replacing the lift pump..

Tony

[Author]

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