'99 150 vmax surging

[Bullseye]

I am having a problem with engine surging during hard acceleration. The engine starts and idles fine. It will accelerate normally for about 2-3 seconds, then loses power abruptly for about 2-3 seconds, then accellerates again. This cycle repeats itself unless I cut back on the throttle.

I can accellerate very gradually and eventually get the boat to full speed with out surging. The engine seems to run strong at full speed if I can get there, but it has cut out once or twice.

It acts like a clogged filter, but I wouldn't expect the prolonged high speed operation. I'm not very familiar with fuel injection, so I'm wondering if this could be the problem.

Any help will be greatly appreciated!

Thanks,
Greg

[boats.net]

If it's an EFI engine then have the fuel pressure tested, test throttle position sensor and check adjustment.

[Bullseye]

Thanks for the suggestions! It is an EFI engine.

The boat is located in a fairly remote area with no dealers close by. I was hoping it might be something I could check, but the "throttle position sensor" is something I'm not familiar with. Is there a simple way to check it?

Thanks!

[boats.net]

It can be tested with a voltmeter, analog meter works best for testing and a digital voltmeter works best for adjusting. You would need a service manual for testing and adjustment specs.