Indmar 5.7 GM 350 engine issues with VIDEO. Is this "Limp Mode"

itsmetibbs

Seaman
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May 24, 2016
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Is this what limp mode sounds like on a boat? VIDEO

I just purchased a new to me 1995 Mastercraft Prostar 205 with an Indmar 5.7L GM 350 Engine with Electronic Fuel Injection. We lake tested it last weekend, and immediately after we left the marina harbor, I started videoing because it would't go above 2000 RPMs. I'v read that this may be a sign that the boat is entering limp mode.

We turned the boat around immediately and returned it to the marina.

I'm going to spend the day today trying to track down electrical gremlins. Maybe this will help me figure out why it's doing this. Any thoughts would be appreciated.

https://youtu.be/tCbBKCJYeCg
 

GA_Boater

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Please don't start more than one thread on the same issue.
 

Bondo

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Ayuh,.... What is the god awful screechin' noise nearer the end,..??

That don't appear to be in limp mode, it appears to be in serious need of a qualified Mechanic,....

The knockin' noises in the beginin' might be detonation, from a lean condition,....
 

itsmetibbs

Seaman
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May 24, 2016
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Wanted to give everyone an update. Turns out my timing chain was not installed properly by the previous owner. The chain was one link off causing all sorts of issues with the valves. I fixed the timing chain and reset my ignition timing and took it out this weekend. It was amazing.

This is my first time driving a direct drive boat, and my first time with a V8. I was amazed at the power and responsiveness. Regretfully, it only ran well for a short time. After about 20 minutes of towing tubers around, we killed the engine and switched riders. When I went to start it again, it wouldn't start. I pulled the cover and saw that we were getting fuel through the Electronic Fuel Injectors. We cranked on it for a bit, and waited, then cranked again, and waited, then cranked again.

After 5 minutes of intermittent waiting and cranking, I was just about to try and flag someone down for a tow when it started up. We kept the guys out on the tube, and started to tow them into the marina, but while towing them in, the engine wouldn?t rev above 2500 RPMs, but it sounded like the engine was running just fine, it simply lacked power.

I made a video trying to replicate the issues without any luck. I'll post the video as soon as it uploads to Youtube.

A friend of mine said he?s thinking it?s a fuel issue caused by the fuel pump. Any thoughts here?
 

Bondo

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Ayuh,.... Examine the contents of the fuel filter, for anything but clean fresh gasoline,....

Then put on a new fuel filter,....
 

itsmetibbs

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May 24, 2016
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I'll examine the fuel filter and have a look at the fuel pump. I'll return and report what I find. In the meantime. Here's a video of the boat running in my driveway after it struggled on the lake. It looks to run fine. I was trying to recreate the no start conditions in my driveway, but I wasn't able to.

https://youtu.be/h80EUg9i5UE
 

Bondo

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Ayuh,.... Yer "Test" is meaningless, as the motor will run just fine, without a Load on it,....

It ain't burnin' no gas to speak of,....

Put a load on it, 'n fuel usage sky-rockets, hence the miss, for a lean condition,...
 

itsmetibbs

Seaman
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May 24, 2016
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Quick update. One mechanic suggested that my problem might be due to the fact that I have an exhaust leak. That leak may be filling up the dog house, and not allowing the engine to breathe. I'm going to lake test it without the doghouse on while I wait for the new fuel pump and filter to arrive.
 

Bondo

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I'm going to lake test it without the doghouse on

Ayuh,..... I've got a Better idea,.....

Fix the exhaust leak, before ya burn yer boat to the waterline,....
 

itsmetibbs

Seaman
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May 24, 2016
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Fixed the exhaust leak, and got back to diagnosing the engine problems.

I was able to pull some check engine codes using the LED/paperclip technique. I see 2 codes.

Code 14: Coolant Temperature Sensor (CTS) Temperature Low
and
Code 33: Manifold Absolute Pressure (MAP) Signal Voltage High

I'm going to do some research to see what I need to do to address these codes. I started the engine up after trying to clear the codes, and it seemed to have affected my timing. Did I mess with any of the timing by putting it in service mode?
 

89retta

Senior Chief Petty Officer
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Jul 18, 2010
Messages
772
Have you checked to see if you water in the oil ? Noticed you have a problem on the port side of the engine. In your video you can see fuel being sprayed up from the back pressure. Don take your boat out till its fixed. That's a major fire hazard
 
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