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HELP! Fuel Problem boat sputters out. Replaced Relay, ECM and Fuel Pumps


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Hi all, I have a complex (at least to me) fuel problem. I have been searching this forum and the internet for a month and can't figure it out. 

Boat is a 2012 Malibu VLX with the Indmar Monsoon 350 Engine. 

Let me start from the beginning.

Boat ran great last year until I winterized it. I noticed after winterizing when trying to run the antifreeze through the boat that it would crank and not run. 

When summarizing, it had the same problem. The boat would crank crank crank all day and not start. 

I replaced (in order) the fuel pump relay, ECM and now the entire in tank fuel assembly (both pumps, regulator etc). 

I was able to get it to start after replacing the ECM by turning the accessory power on then off and on again (almost like it was building pressure each time) until it starts. It would then run as long as you want it to until you turn it totally off. When you turn it off the next time you start it, it runs for about 3 seconds and sputters off. You must then do the on, off,on,off to get it to start again. I have replicated this multiple times. 

I put the old ECM back on it and replicated the results (eliminating the ECM). 

This is when I replaced the fuel assembly in the tank and still have the same results.

Fuel pressure at rail is 60psi when pump is running.

Any advice would be very much appreciated! 

Edited by Dorward
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Dealer is about an hour away. I have messed with the lanyard and it appeared to be working properly but I will short it to verify. 

Thanks!

 

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Found this post that explains similar condition: 

I am going to try the crankshaft position sensor tomorrow.  Running out of things to throw money at...

 

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Im not familiar with this model, but does it use a fuel pressure regulator? If so, could it be bad and allowing too much pressure? 60 psi is a lot but that model may be designed for that while my 01 is designed to be regulated to 45 psi. 

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On April 18, 2017 at 1:33 PM, Dorward said:

Hi all, I have a complex (at least to me) fuel problem. I have been searching this forum and the internet for a month and can't figure it out. 

Boat is a 2012 Malibu VLX with the Indmar Monsoon 350 Engine. 

Let me start from the beginning.

Boat ran great last year until I winterized it. I noticed after winterizing when trying to run the antifreeze through the boat that it would crank and not run. 

When summarizing, it had the same problem. The boat would crank crank crank all day and not start. 

I replaced (in order) the fuel pump relay, ECM and now the entire in tank fuel assembly (both pumps, regulator etc). 

I was able to get it to start after replacing the ECM by turning the accessory power on then off and on again (almost like it was building pressure each time) until it starts. It would then run as long as you want it to until you turn it totally off. When you turn it off the next time you start it, it runs for about 3 seconds and sputters off. You must then do the on, off,on,off to get it to start again. I have replicated this multiple times. 

I put the old ECM back on it and replicated the results (eliminating the ECM). 

This is when I replaced the fuel assembly in the tank and still have the same results.

Fuel pressure at rail is 60psi when pump is running.

Any advice would be very much appreciated! 

hook up your fuel pressure gauge and take a fuel sample form the fuel rail. if your pressure gauge has a bypass.  Im guessing you have water in your fuel? water will settle to bottom of fuel tank and get pumped first. take about 1 pint of fuel into a GLASS container and let it sit for 30 min or so.  you should see NO separation for good fuel.

 

or jack up the front of the boat high. and siphon out some fuel, try to get it from the bottom of the tank. maybe pull one of the 2" fuel inlets... i 3/8 fuel hose and a outboard primer bulb work great.

 

good luck. 

  • Like 2
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Do you have spark? This is ALWAYS the first place to start. Unless you know a part is bad, replacing it will almost never help (if it does, buy a lottery ticket ASAP).

Once you confirm spark, then start measuring fuel pressure, testing injectors, etc. A simple test is to pull a spark plug and look for wet fuel on the plug.

if all this checks out, you probably have bad fuel. A squirt bottle of gas down the throttle body CAREFULLY will help test this. If you want to get carried away to can disconnect your fuel tank and run the hose into a fuel can of FRESH brand new gas. If the engine starts after that, siphon out all your fuel, dump in an entire bottle of water treatment and then add fresh gas.

 

good luck!

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I forgot to post what actually fixed the issue. It was the crank position sensor. The sensor was not sending signal to the ECM that the crank was turning, therefore the ECM wasn't telling the fuel pump to send fuel. 

That being said, I have a the old fuel pump that still works fine if anyone is looking for one I also put the new ECM on ebay. 

  • Like 3
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