2009 225hp pro xs fuel pump replaced after 64hrs......Don???

[kevcol]

I had little power (couldn't get on plane) last time I had boat out. Took to dealer and they replaced high pressure fuel pump. Fuel pressure test found only 25psi. This is what the work order said then: "pulled vst tank off and checked both boost and high preasure pumps and the high pressure pump was low. Replaced high pressure pump and performed pressure test again, 90psi on gauge. Engine was only running on 5 cylinders, switched plugs and was not the problem, switch coils and the engine started running on all 6 cylinders. Water tested and ran great." Is everything sounding ok here???? I'm no expert, just want to double check. Comments................

[EuropeanAM]

Sounds like the later end was the actual "cause".

Fuel pressure must be taken WITH THE ENGINE RUNNING. Pressure test with engine "static" (not running) will show low fuel pressure EVERY TIME, since fuel pressure is dependent on AIR PRESSURE (fuel pressure equals AIR PRESSURE PLUS 15 PSI).

[kevcol]

Sorry Don, I'm a little confused. I think you are saying that quite possibly there was not a problem with high pressure pump. I guess my problem is that I do not understand the part where they say the engine was only running on 5 cylinders, switched plugs, coils etc..... Could you explain this to me briefly in a way a novice would understand.

[EuropeanAM]

Sorry about that.... I'll try to be a little more clear.

Can't say for certain that the fuel pump was, or was not bad. Simply stating that there MAY have been an error in the diagnostic proceedures.

As for the other part of what you were told- it sounds like you had an ignition coil that was producing no spark. This meant that one cylinder was not firing, and thus not producing power. This scenario I do not doubt.... and likely corrected your problem.