1994 LT-1 Loses Power Under Load - Sometimes

[sheyski]

We have a 1994 Prostar 205 with LT-1 engine. Every so often, our boat decides to play games with us. It's been doing this for several years. It happened before we replaced our fuel pump 2 or 3 years ago, (which was also causing other issues) and it continues sporadically today. We can go weeks without an issue, then this problem will happen once, then we go for weeks with no issue again.

I will be idling in the water for a minute or two, waiting for the skier to get ready. I put the boat in gear, then they yell "go boat" and I push down on the throttle. It starts to take off for about a second, then cuts out like it went into limp mode - the power just cuts out. I can put it back into neutral, try again....same problem. So I either shut the motor off or leave it running and wait 30 seconds, try again and everything is fine. Once the skier is up, no issues with it running. It's only at take off. The boat ran just fine on Memorial day weekend for our show, so not sure why it pulled this on Saturday.

A few years ago, we found what looked like a large bug floating in our gas tank, so we dumped all the gas, removed the bug and things seem to work ok for quite some time.

I have had this problem pulling a pyramid off the dock (they are never happy when THAT happens...imagine 8 skiers/climbers all falling instantly). It happened once this weekend while pulling a sit skier and 2 side skiers. A few years ago, it happened while pulling a wakeboarder. He fell, I went back to pull him again and the boat wouldn't take off. It took a few attempts and finally I was able to take off.

Any tips to resolve this pesky little issue?

Thanks!

[mgs96ps]

......

[sheyski]

BTW...did you fix your cooling issues. I would put on new fuel filter, ( the one on the rail), check to see if you have an in line filter on top of tank and replace that, check for clog in primary fuel pump inlet screen. After that maybe run some sea foam in tank. Maybe check fuel pressure at rail. Basically I would eliminate it being a fuel issue and then move to spark issues.

Cooling issue is something we will be working on this week. We brought the boat home after our clinic this weekend so we can work on trailer and boat. He's anxious to reroute the hoses according to Mastercraft fix, and see if that helps. We'll also look at the hoses to make sure none are collapsing from the inside.

How do we determine the fuel pressure? That is not something my hubs knows how to do.

What does "the rail" mean? "I would put on new fuel filter (the one on the rail)?"

Shey

[Ski-me]

My first guess would be the pump again. Do you have another inline filter at the gas tank, too? The first "filter" from the tank to the pump is the screen at bottom of pump. You might add an in-line filter at the tank and then pull the pump out and clean the intake screen.

[Ski-me]

Cooling issue is something we will be working on this week. We brought the boat home after our clinic this weekend so we can work on trailer and boat. He's anxious to reroute the hoses according to Mastercraft fix, and see if that helps. We'll also look at the hoses to make sure none are collapsing from the inside.

How do we determine the fuel pressure? That is not something my hubs knows how to do.

What does "the rail" mean? "I would put on new fuel filter (the one on the rail)?"

Shey

The "rail" filter is on the back of the engine area, just past your fuel pump. After the filter, it goes into the fuel rail on each side. There is a shrader cap where you could tie in a fuel pressure gauge.

[mikeg205]

Have u ever cleaned the fuel pump inlet screen?


Sent from my iPhone using Tapatalk

[mgs96ps]

......

[sheyski]

My first guess would be the pump again. Do you have another inline filter at the gas tank, too? The first "filter" from the tank to the pump is the screen at bottom of pump. You might add an in-line filter at the tank and then pull the pump out and clean the intake screen.

I know we have the first filter you mentioned. I'm not sure about an inline filter. Are you suggesting there might be a filter at the top of the tank on the same assembly?

Any pictures on this might be helpful so we can compare (if anyone has one).

[sheyski]

Have u ever cleaned the fuel pump inlet screen?

Probably not this year, but I think he did that in the past. I'll check and find out.

[sheyski]

See picture.

Thanks for the image! That is always helpful

[sheyski]

The "rail" filter is on the back of the engine area, just past your fuel pump. After the filter, it goes into the fuel rail on each side. There is a shrader cap where you could tie in a fuel pressure gauge.

Can you use any fuel pressure gauge? I'm assuming this is something I can pick up at O'Reilly's perhaps?

[Ski-me]

Can you use any fuel pressure gauge? I'm assuming this is something I can pick up at O'Reilly's perhaps?

Yes, I think so. You can remove the cap cover of the valve and take it in so you have the correct thread size to make the attachment. Tell them you are testing the fuel pressure.

I added an in-line filter at tank (I did not originally have one). I'll try and find a link for you.....

[mgs96ps]

......

[Ski-me]

I think there is a picture in here (can't see at work)....

http://www.mastercraft.com/teamtalk/showthread.php?t=51183&highlight=tank+fuel+filter&page=8

[sheyski]

BTW...just curious. Are you running ethanol gas? Also referred to as deathanol. Not trying to start a gas debate...but I would recommend at least 91 octane and ethanol free.

Yeah, my hubs is an automotive machinist and a purist He's seen the damage too often when repairing engines. We only use 91 octane in there.