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Tim.Doyle
06-21-2010, 05:51 PM
My 95 Prostar will loose power at high end after a few hours of quality running. Will then take power then die off, then surge into power. Eventually will only idle home.

Andre's post here describes very similar issue.
http://www.mastercraft.com/teamtalk/showthread.php?t=17776

I have trouble shot most of the commonly refered to causes if TBI power issues.

All Filters are clean

No Moisture in MAP Sensor

Cleaned Gas Tank

Used new gas, Etc...

One issue that seems to be a potential would be that one of the injectors seems to be faulty, it pours gas more than sprays it as the other does. Any thoughts?

Additionally does anyone know if the injectors are the same part as the automotive version? May be cheaper that way?

Thanks
Tim

JimN
06-21-2010, 11:15 PM
My 95 Prostar will loose power at high end after a few hours of quality running. Will then take power then die off, then surge into power. Eventually will only idle home.

Andre's post here describes very similar issue.
http://www.mastercraft.com/teamtalk/showthread.php?t=17776

I have trouble shot most of the commonly refered to causes if TBI power issues.

All Filters are clean

No Moisture in MAP Sensor

Cleaned Gas Tank

Used new gas, Etc...

One issue that seems to be a potential would be that one of the injectors seems to be faulty, it pours gas more than sprays it as the other does. Any thoughts?

Additionally does anyone know if the injectors are the same part as the automotive version? May be cheaper that way?

Thanks
Tim

Find a way to check the fuel pressure. That's always the first thing to check whenever performance issues arise. Also, verify base timing, while you're working on it. Your pressure should be about 20 lb and the four tests MC recommended are Key ON- engine OFF, Idle, 2000 RPM and WOT (Wide Open Throttle). It shouldn't drop below 18 lb at any time and definitely not for any length of time. If it dips, it should jump right back up to normal.

Generally, if the pressure is low, it will look more like a heavy stream than a thin cone. High pressure causes the fuel to atomize more than low pressure.

Your tank should be below the center section of the rear seat- remove the fuel pickup and look at the screen on the end (it may just have a coiled wire in the tube). Of you see any debris, clear it out. Also, the aluminum part that threads into the rectangular block on the pickup tube is a check valve- clean that out, too. Make sure the fuel line going from the tank to the pump isn't under the tank and being pinched. If the motor runs better with less fuel in the tank, this is a possibility.

duffcam
06-22-2010, 05:55 PM
pull the injectors, clean or replace the garter screens & it'll probably fix. you can reuse the gaskets/screens if yuur really careful/gentle on teardown, the screens can be removed from the injectors & carb sprayed clean. when through add a can of SF16 Seafoam to the tank, I found a TBI repair kit from Borg Warner with replacment gaskets/screens. if you need the part # I'll try to find it, it was a 94-95 big block (454) variety. really an easy job & your injectors are probably not bad

jimmer2880
06-22-2010, 09:44 PM
Before you do all of that, I would check the inlet screen on your fuel pump. It will only take 15 minutes to check/clean. This problem sounds similiar to the age old problem with the mid-90 era boats of clogged fuel pump screens.