2003 496 HO how many fuel filters are there? Where?
07-16-2018 | 08:46 PM
#1
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2003 496 HO how many fuel filters are there? Where?
Folks,
i am trying to diagnose a top end power / RPM issue and I'm a little lost. boat sat 2 years with a full tank of gas. I'm down to about 75 gallons of 2 year old fuel. The motor runs great up to 4000 rpm so I'm cruising around trying to burn the old gas. I will add fresh gas and see if that helps, but am starting to think I have another issue. I just purchased a fuel pressure test kit but won't be back to the boat for 2 weeks. So I don't know for sure if I have a fuel pressure issue or not. I changed the inline filter and the water separator. I am researching now and see something called cool fuel. Apparently this module has a filter or two. Where is this module located on the motor? Were are the filters? I see a ton of info on the gen 3 cool fuel issues but I believe my 2003 pre dates the gen 3. Does this make mine gen 2?. The 2 filters I changed were super clean. No crap in either one. What is up stream? Does the fuel flow from tank through in line filter then water separator to cool fuel to the EFI? Is the cool fuel the fuel pump or is there a pump in the tank? Holy **** I have more stupid questions than 3 wise men can answer. Hopefully we have more than 3 wise men on this forum. Thanks in advance for any info.
Kevin
i am trying to diagnose a top end power / RPM issue and I'm a little lost. boat sat 2 years with a full tank of gas. I'm down to about 75 gallons of 2 year old fuel. The motor runs great up to 4000 rpm so I'm cruising around trying to burn the old gas. I will add fresh gas and see if that helps, but am starting to think I have another issue. I just purchased a fuel pressure test kit but won't be back to the boat for 2 weeks. So I don't know for sure if I have a fuel pressure issue or not. I changed the inline filter and the water separator. I am researching now and see something called cool fuel. Apparently this module has a filter or two. Where is this module located on the motor? Were are the filters? I see a ton of info on the gen 3 cool fuel issues but I believe my 2003 pre dates the gen 3. Does this make mine gen 2?. The 2 filters I changed were super clean. No crap in either one. What is up stream? Does the fuel flow from tank through in line filter then water separator to cool fuel to the EFI? Is the cool fuel the fuel pump or is there a pump in the tank? Holy **** I have more stupid questions than 3 wise men can answer. Hopefully we have more than 3 wise men on this forum. Thanks in advance for any info.
Kevin
07-17-2018 | 09:09 AM
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From: Tygart Lake, WV
Folks,
i am trying to diagnose a top end power / RPM issue and I'm a little lost. boat sat 2 years with a full tank of gas. I'm down to about 75 gallons of 2 year old fuel. The motor runs great up to 4000 rpm so I'm cruising around trying to burn the old gas. I will add fresh gas and see if that helps, but am starting to think I have another issue. I just purchased a fuel pressure test kit but won't be back to the boat for 2 weeks. So I don't know for sure if I have a fuel pressure issue or not. I changed the inline filter and the water separator. I am researching now and see something called cool fuel. Apparently this module has a filter or two. Where is this module located on the motor? Were are the filters? I see a ton of info on the gen 3 cool fuel issues but I believe my 2003 pre dates the gen 3. Does this make mine gen 2?. The 2 filters I changed were super clean. No crap in either one. What is up stream? Does the fuel flow from tank through in line filter then water separator to cool fuel to the EFI? Is the cool fuel the fuel pump or is there a pump in the tank? Holy **** I have more stupid questions than 3 wise men can answer. Hopefully we have more than 3 wise men on this forum. Thanks in advance for any info.
Kevin
i am trying to diagnose a top end power / RPM issue and I'm a little lost. boat sat 2 years with a full tank of gas. I'm down to about 75 gallons of 2 year old fuel. The motor runs great up to 4000 rpm so I'm cruising around trying to burn the old gas. I will add fresh gas and see if that helps, but am starting to think I have another issue. I just purchased a fuel pressure test kit but won't be back to the boat for 2 weeks. So I don't know for sure if I have a fuel pressure issue or not. I changed the inline filter and the water separator. I am researching now and see something called cool fuel. Apparently this module has a filter or two. Where is this module located on the motor? Were are the filters? I see a ton of info on the gen 3 cool fuel issues but I believe my 2003 pre dates the gen 3. Does this make mine gen 2?. The 2 filters I changed were super clean. No crap in either one. What is up stream? Does the fuel flow from tank through in line filter then water separator to cool fuel to the EFI? Is the cool fuel the fuel pump or is there a pump in the tank? Holy **** I have more stupid questions than 3 wise men can answer. Hopefully we have more than 3 wise men on this forum. Thanks in advance for any info.
Kevin
Genuine Mercury & Mercruiser parts
07-17-2018 | 09:38 AM
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Awesome. Thanks for the input. Just curious why you are so adamant about the pumping out the fuel? Do you think that is the problem? I'm thinking that if the fuel was the entire problem it would struggle to get the boat on plane. i also don't have an easy way to pump this fuel out and I don't know what to do with 80 gallons of old fuel.
07-17-2018 | 09:57 AM
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From: Central IL
2 year old untreated fuel is low octane garbage. If the engine is detonating on the old fuel the PCM will be pulling timing out causing the poor top end performance. You can easily pump old fuel out of the boat and have your buddies line up for free gas in their cars/trucks/lawn mowers/etc.
07-17-2018 | 09:59 AM
#5
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From: Ft. Worth TX
Stock oem is Gen 2 cool fuel.
Go buy a portable gas tank - like for outboards -- going to need it for winterizations anyways - with that buy quality fuel line and quality primer bulb- fill with current fresh fuel - run engine using your new portable gas tank supply to take the complete boat fuel side out of the mix. by doing so your bypassing 8 possible issues here. Yes bad gas is one of issues in the mix for the possibilities.. This how many good techs in the industry start out the testing procedures to pin point issue bare none. Such a fast and easy and non expensive ways for great testing results and pin pointing areas of concern,
This will tell you what side of the boat your issues are. Boat side or engine side.
Stock engine - Tech speaking there is 10 filters in the mix --- you have 2 fuel filters and then there is 2 screens in the mix. So guess were the 8 other filters are ???
Go buy a portable gas tank - like for outboards -- going to need it for winterizations anyways - with that buy quality fuel line and quality primer bulb- fill with current fresh fuel - run engine using your new portable gas tank supply to take the complete boat fuel side out of the mix. by doing so your bypassing 8 possible issues here. Yes bad gas is one of issues in the mix for the possibilities.. This how many good techs in the industry start out the testing procedures to pin point issue bare none. Such a fast and easy and non expensive ways for great testing results and pin pointing areas of concern,
This will tell you what side of the boat your issues are. Boat side or engine side.
Stock engine - Tech speaking there is 10 filters in the mix --- you have 2 fuel filters and then there is 2 screens in the mix. So guess were the 8 other filters are ???
Last edited by BUP; 07-17-2018 at 10:38 AM.
07-17-2018 | 10:09 AM
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How can I pump the fuel out? Disconnect the line running to the fuel rail and use the boats electric pump to pump the fuel out through a long pieces of fuel line into my truck? I suppose this is possible. Is there another idea?
Kevin
Kevin
07-17-2018 | 10:20 AM
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OK that makes perfect sense. I wasn't following the portable fuel system until you just said like the outboard fuel tanks. This also didn't make sense to me earlier as I thought the fuel pump was located in the tank. I did not know anything about the 2 pumps and the cool fuel module. So this will eliminate the 2 year old gas completely, well almost just what's in the line and fuel and fuel rail. I am sure the other 8 filters you talk about are each injector.
Thanks for the input I feel like I have a plan now. I am going to run it on a portable source with fresh gas and see how she runs. If that is the problem I am going to have a gas sale in Alexandria Bay NY.
If this is not the problem I have ordered a fuel pressure test gauge set up and have ordered the factory service manual that will allow me to further diagnose the problem and start working my way through the fuel pump screens low and high pressure as well as pulling the injectors and the fuel rail. I will only take these steps if running on a portable fuel source doesn't solve my problem.
Does this sound like a good plan?
Kevin
Thanks for the input I feel like I have a plan now. I am going to run it on a portable source with fresh gas and see how she runs. If that is the problem I am going to have a gas sale in Alexandria Bay NY.
If this is not the problem I have ordered a fuel pressure test gauge set up and have ordered the factory service manual that will allow me to further diagnose the problem and start working my way through the fuel pump screens low and high pressure as well as pulling the injectors and the fuel rail. I will only take these steps if running on a portable fuel source doesn't solve my problem.
Does this sound like a good plan?
Kevin
07-17-2018 | 10:36 AM
#9
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From: Ft. Worth TX
mercruser has never done any fuel pumps in the gas tank. You have 2 external fuel pumps. Strongly will have to say you NEED to buy the correct OEM service manuals. I have them all and know which correct ones are needed.
I am at lost why boaters work on their own apps without service industry material. This is just asking for failures without proper OEM material and procedures to follow along and learn. No offense just making true statements.
I am at lost why boaters work on their own apps without service industry material. This is just asking for failures without proper OEM material and procedures to follow along and learn. No offense just making true statements.
07-17-2018 | 10:38 AM
#10
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Just buy a 12V cheap ($25 or less) fuel pump from Advance Auto or the like, and temporarily plumb it into your fuel system, before the motor. Hook it up to a jump back with a long pair of wires so you can stand outside the boat, and turn it on/off with the jump pack power switch, (with no sparks).
Remember, fuel pumps like to push fuel not pull it. Shortest hose/closest location to the fuel tank; and a long hose out over the side of the boat to your 55 gallon drum, truck, or whatever.
I've done this quite a few times; even built a quick setup for it. This method is not rocket fast, but it works well.
Remember, fuel pumps like to push fuel not pull it. Shortest hose/closest location to the fuel tank; and a long hose out over the side of the boat to your 55 gallon drum, truck, or whatever.
I've done this quite a few times; even built a quick setup for it. This method is not rocket fast, but it works well.
