View Full Version : 1996 prostar indmar 5.7 losing power and surging

09-08-2013, 01:30 PM
fuel injected engine starts good, runs good
but then...
after using 6-7 gallons of gas, maybe 1.5 hours time
the engine will not rev to full power
if I throttle up, it will decrease power and thus speed
If I throttle down some it will increase power and speed
I can only maintain about 20 mph without any issues
it will hesitate some coming back up to throttle at 20 mph
if I put the throttle down it will surge tremendously as if not getting fuel and then getting all she wants, oil pressure jumps back and forth, ( as I would expect)
temperature is fine, not overheating
checked and replaced inline fuel filter, cannot find any indication of water
fuel pump screen clear

I can come back next day and same thing happens
everything starts out fine but then the problem will repeat itself

anyone familiar with this problem?