View Full Version : Motor Surging

05-24-2010, 05:13 PM
Someone has prob had this problem before but I can't find a thread so I will post looking for answers. Took the boat out this weekend. Prostar 205 LT1 580 Hours.....was running fine on Saturday then Sunday (of course when I was having my lake party) ran like crap. When I tried to get up on plane the engine would start serious surging. Was never able to get over 15 mph. Just put in new gas and treatment. When the engine reved (not in gear) it would always reach around 4000 rpm then start surging. was having a problem similar to this at the end of last year and took it to Chuck at Bay Area. They said it was the fuel screen filter and fixed it also replaced the impeller and serpentine belt. Ran great for awhile, now here I am again. Just trying to see if there is an easy fix before I take it back to Chuck because budget a little tight right now. I thank you in advance for the suggestions.

05-24-2010, 05:26 PM
I'd check the fuel filter again and also have your fuel pressure checked. Might be signs of a fuel pump about to quit.

05-24-2010, 05:51 PM
I'm guessing fuel as well, but only for one reason. If you run it in gear(under a load) and it surges but then you take it out of gear and it's smooth that would be computer. If it will stall/cut-out/surge in Neutral than its starving for gas. It may be starving because of a blockage of the fuel filter or some other element in the gas itself(water).

05-24-2010, 06:17 PM
Change the fuel filter first--if that doesn't fix it then take it to the dealer. I would also pull a sample of fuel out of the filter to look at it.

05-25-2010, 09:45 PM
Yup, its fuel related, most likely. Easy thing is the filter, and its cheap. Just replace it. Also may want to drain your fuel tank and see if there is water in it. Could be injectors or ECU worse case scenario... I would recommend running a injector cleaner solution through the tank and engine.

05-30-2010, 10:31 PM
Mine surges both in neutral and at low rpm. Fuel filter or computer?

05-30-2010, 11:01 PM
Check the throttle position sensor. Put a voltmeter on it and watch the volts while you turn the throttle should be smooth, not jumpy

05-30-2010, 11:10 PM
The trottle position sensor was just replaced, but thanks for the reply.

05-31-2010, 08:28 AM
Another note about the surging; it will correct itself, albeit for a short period of time, when I turn the engine off. If the problem is with the computer, would it not throw a code?