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peterman

95 Sunsetter Loosing Power At Times?

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peterman

Hello. I am a new malibu owner, but not new to boating. I have a 95 sunsetter that I bought last year from my aunt. My uncle bought it new and has meticulously maintained it until he passed away 7 years ago. My aunt kept the boat and periodically maintained it, (to the best of her ability) after he passed away.

It was ran for 4 years every summer after my uncle passed away, then sporadically ran the summer before I bought it. She told me it ran fine the year before with no problems. It was winterized the year before I got it from her.

It started up and ran great when I put it in the water last year for the first time. I had to put some fresh gas in it to top it off before I got to the lake. I changed the fuel water separator before I put it in the water. I noticed a bunch of black flakes in the filter when I took it off. It ran great for about a half hour and then started to cut out under load. When it was in full throttle, it would spudder. When you put it in neutral, and back on the gas it takes right off. After a short time, about 3 mins or so it does it again.

So I took it to a local marine mechanic to check it out. He was able to reproduce the same problem and diagnosed it with low fuel pressure at the injectors. His fix was to remove the injectors and have them sent off to be cleaned. In my extreme inability to wait until the injectors came back (3 weeks to a month being sent to Florida) and the fact that our summers where I live are not very long, I went and bought some automotive injectors, (not marine grade, which I heard is a no no) and had him install them. No change in performance. I have yet to put the original injectors back in.

I see he had the vapor separator rebuilt about 150 hrs ago, a new fuel pump about 50 hrs ago, inspected the fuel tank sending unit about 50 hrs ago.

Sorry to ramble, but I have looked at alot of threads here and have seen some possibilities that might be the culprit but I'm not 100% what the issue might be. So can anyone shed some light on what might be the issue. Any help is appreciated.

Edited by peterman

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Steve B.

"I see he had the vapor separator rebuilt about 150 hrs ago, a new fuel pump about 50 hrs ago, inspected the fuel tank sending unit about 50 hrs ago."

I'm not sure what the issue might be, but based on the above statement, I think your uncle was experiencing the same thing, and continually trying to find the issue.

Steve B.

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Murphy8166

Had the same issue with mine at one point. It was the fuel pump.

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CoMtnBu

Our problem was the injectors where dirty. I'd put the clean OEM injectors back in along with new fuel filters and give her a run.

Then I'd start trouble shooting.

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peterman

Thanks for the info guys. I figured since the fuel pump was replaced 150 hrs ago that wouldn't be a issue. I know its a boat and things are replaced sooner than a vehicle but I wouldnt think that soon. I also noticed the vst was worked on a few times in his maintenance log so I wondered about that. I will put the oem injectors back in and replace the fuel filter and see how she goes. If that's not it I will go from there. Thanks again.

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jweloc

Because of the sporatic usage and not knowing exactly how it was winterized, I would say it's the injectors also. One of the most important steps, but often underestimated by unknowing owners, is to skip the gas treatment process when winterizing. New Fuel filters and a rebuilt seperator won't help if $%#@&^ gas has gummed up the fuel delivery.

Edited by jweloc

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electricjohn

If the problem was diagnosed as low fuel pressure, why haven't you looked into the fuel pressure regulator?

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peterman

If the problem was diagnosed as low fuel pressure, why haven't you looked into the fuel pressure regulator?

I didn't think of that. I am not to bad mechanically, but I would have figured the mechanic who does boats solely for a living would have looked at that when it was taken to him. Thanks for that tip, because that might be a great place to start. Is that a expensive fix?

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Steve B.

Interesting though, it seem's to run fine when cold or warming up. Just wondering if it might be upper rpm or under load weak spark or sputtering.

You did change the gas, hm. You know what I'd do first, clean the umbelical connections, and make sure the battery connections are what they should be. Make sure the plugs are gapped. Does it just sputter at rpm or does it drop the rpm dramactically?

Let us know,

Steve B.

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peterman

Interesting though, it seem's to run fine when cold or warming up. Just wondering if it might be upper rpm or under load weak spark or sputtering.

You did change the gas, hm. You know what I'd do first, clean the umbelical connections, and make sure the battery connections are what they should be. Make sure the plugs are gapped. Does it just sputter at rpm or does it drop the rpm dramactically?

Let us know,

Steve B.

Steve, I put new gas in it when I took it out at the beginng of summer. This happens off and on at mid rpms. It will start to loose power and will loose mph. When you throttle wide open, it appears to want to backfire/spudder. When you put it in neutral and get back on it, it seems ok for awhile. What is the umbelical connections?

Brian

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peterman

Interesting though, it seem's to run fine when cold or warming up. Just wondering if it might be upper rpm or under load weak spark or sputtering.

You did change the gas, hm. You know what I'd do first, clean the umbelical connections, and make sure the battery connections are what they should be. Make sure the plugs are gapped. Does it just sputter at rpm or does it drop the rpm dramactically?

Let us know,

Steve B.

Steve

I didn't mention it has 990 hrs on the motor, if that matters. Great maintenance by my uncle though.

Brian

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martinarcher

I had a similar issue with my Sunsetter and chased fuel delivery for quite a while because of the way it would fall on it's face and sputter. It ended up being the ignition coil. Very cheap thing to change. It would get warm and not deliver proper voltage to the distributor and cause weak spark. In turn, the engine would loose power and act as you describe. The longer we sat and let the engine cool off the longer it would run before acting up again. Might not be your issue, but worth noting and keeping in mind in case it is since coils are awful cheap compared to fuel pumps and other fuel system parts.

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peterman

I had a similar issue with my Sunsetter and chased fuel delivery for quite a while because of the way it would fall on it's face and sputter. It ended up being the ignition coil. Very cheap thing to change. It would get warm and not deliver proper voltage to the distributor and cause weak spark. In turn, the engine would loose power and act as you describe. The longer we sat and let the engine cool off the longer it would run before acting up again. Might not be your issue, but worth noting and keeping in mind in case it is since coils are awful cheap compared to fuel pumps and other fuel system parts.

I had read on here somewhere that it could be a ignition coil. Thanks for that. I think when I decide to get it ready this spring I will put the factory injectors back in and put a new coil in. Can you put a Chevy 350 throttle body injector coil in at any parts store, or is there a marine grade version like some other parts on the motor that is required?

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peterman

I had a similar issue with my Sunsetter and chased fuel delivery for quite a while because of the way it would fall on it's face and sputter. It ended up being the ignition coil. Very cheap thing to change. It would get warm and not deliver proper voltage to the distributor and cause weak spark. In turn, the engine would loose power and act as you describe. The longer we sat and let the engine cool off the longer it would run before acting up again. Might not be your issue, but worth noting and keeping in mind in case it is since coils are awful cheap compared to fuel pumps and other fuel system parts.

When mine cuts out like that, I can put it on neutral, and put it back in drive and it takes off again for awhile and then will go back to cutting out. Did you experience anything like that to? Just curious if it might also be a throttle cable issue? Coil sounds more like it I guess.

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Steve B.

To me, sputtering means the fuel isn't being burned correctly, or the introduction of the fuel into the system is crapola, ha.

Hard to troubleshoot often.

The umbelical, is a multi pin connector located near the starter area, that is essentially a jumper cable between the engine and dash.

It's notorious for causing wierd electrical issues. It just pulls apart. Contact cleaner can be sprayed on the connections then remated together. It's so easy, it's a no brainer to do.

I'd also be looking at all electrical connections. At the starter, switch, battery's, etc.

Steve B.

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martinarcher

When mine cuts out like that, I can put it on neutral, and put it back in drive and it takes off again for awhile and then will go back to cutting out. Did you experience anything like that to? Just curious if it might also be a throttle cable issue? Coil sounds more like it I guess.

Yep. Very similar. When it would come on, it would repeat the problem very frequently. Until you gave the coil time to cool off you weren't going to get in any good riding. Cry.gif

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peterman

Yep. Very similar. When it would come on, it would repeat the problem very frequently. Until you gave the coil time to cool off you weren't going to get in any good riding. Cry.gif

Thank you for the info, it is greatly appreciated not only by you but everyone who has posted on here to try and help me diagnose this issue. As I found out, and was already prepared for, shop time is not cheap. So anything I can do myself is a plus.

One more question if you dont mind. I noticed that I had alot of water in my bilge last year, enough for the pump to kick on for what seemed to me to be alot of times when I am out running it. It has a little water in the bilge when I bring it in to the dock and park it for the night. The next time I take it out, the same amount of water is in there as when I put it away for the night, so there seems to be no leaking while it is sitting for a period of time. I have read some threads on here about some possible reasons for that, swim step brackets, rudder, bow eye, etc. The shaft packing was tightened and is dripping at its normal rate so thats not a problem.

As I said in my first post, I am not new to boating. I have been wakeboarding behind my sisters boat for the last 19 years, but its a I/O. So this whole direct drive malibu is a whole new thing to me. Similar in some ways, but a few things different as far as diagnosing some problems.

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skiguy

I suffered a similar problem last summer on my '98 Sunsetter and got a lot of good advice from the folks here. Things to look at:

1. Have you checked the fuel pressure with a fuel pressure gauge? (attaches to a nib just after the fuel pump) - should consistently read 40psi. Take it out for a spin and have a buddy watch the guage as the problem occurs. If pressure drops you have a bad fuel pump or a blockage issue.

2. Have you checked the inlet screen on the fuel pump? It's at the bottom (remove the brass fitting and look inside) of the fuel pump. If the fuel system sat for a long time with old fuel it may be partially blocked with gunk.

3. Did you replace the fuel tank fuel filter? (my '98 has one at the tank and at the fuel pump and it's often overlooked)

4. Did you drain the fuel tank completely? If the old fuel in there sat a really long time and went bad, even diluting with new fuel won't help. To eliminate the fuel as a problem itself you may need to drain completely and start with totally fresh gas.

5. What fuel are you using? My boat hates 87 Octane. The owners manual says 89 Octane and they meant it. :biggrin:

6. Pull the distributor cap and look for symptoms of Arc Tracing (I doubt this is it but it's easy to check)

My issues were solved when I drained the gas and replaced with 89 Octane, Put a new tank filter and fuel pump filter. Hope this is helpful info.

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electricjohn

One more question if you dont mind. I noticed that I had alot of water in my bilge last year, enough for the pump to kick on for what seemed to me to be alot of times when I am out running it. It has a little water in the bilge when I bring it in to the dock and park it for the night. The next time I take it out, the same amount of water is in there as when I put it away for the night, so there seems to be no leaking while it is sitting for a period of time. I have read some threads on here about some possible reasons for that, swim step brackets, rudder, bow eye, etc. The shaft packing was tightened and is dripping at its normal rate so thats not a problem.

If you have an exhaust manifold cooling crossover hose, make sure the coupling is tight.

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