prostreetracer2
New member
New here and so far what a great forum with lots of info. Thinking I may have to subscribe to the online Seloc to keep troubleshooting my issues but it’s good to know it’s there if needed. I have a 2008 Mercury 4 Stroke (Serial # 0R241050) that is having some sort of High Pressure Fuel Pump power issue I think.
Background: I got this pontoon/motor last year and it ran fine up until now. Since I've ran it I've only used 91 octane alcohol free fuel with Star Tron Marine Fuel Treatment. I replaced the old fuel hose from the portable tank to the motor and bulb this year along with replacing the old external fuel/water filter separator.
Background of what happened: Ran the motor for about half hour and then sat in the middle of the lake
for about an hour. Went to go start it and it ran for a second and then died.
After that I tried starting it again and all it would do is turn over. I checked for spark and had spark and check the fuse and it was good. Also checked the battery and it was at 12.6 volts. Eventually was towed in.
Once back I replaced the spark plugs (as a maintenance item), took off the VST and cleaned that and it was really bad (Fuel Pump had rust all over it and was clogging the screen). Hooked the high pressure fuel pump up to a battery to test it and it ran. Put everything back together and still all the engine does is crank.
The next day I checked the fuel pressure rail and there was no pressure. I disconnected the output
on the VST where the pump should be sending fuel into the high pressure side of the system and turned the key and nothing. I then decided to try to jumper the high pressure fuel pump with a small 12v battery. As soon as I connected the little battery fuel sprayed everywhere. Which meant to me that the high pressure fuel pump is good.
I then reconnected the high pressure hose to the VST and then jumpered the high pressure fuel pump to a small battery and the pump ran and a friend turned the key and the engine ran for 15 seconds until I removed the fuel pump jumper wire.
So I’ve narrowed the issue down to I think an electrical issue but I’m not exactly sure as I don’t know enough about boat engines to determine it 100%. Is the high pressure fuel pump tied to anything else to tell it to turn on? Would the pressure regulator valve control the pump at all? I know it opens or something like that when the fuel system is around 40 PSI.
I have the battery right now connected to a charger and its charging and sitting at 12.6 volts still. I read another forum post saying a member had to replace their battery with a similar issue but isn’t 12.6 volts enough? I'm unsure of how old the battery is as I can't find a date code on it but I know it's from Walmart as its an Everstart. I also tried hooking up a jump pack to the motor and it still wouldn't start. I would think with a battery and a jump pack that should be more than enough to eliminate it being a battery issue but maybe not? The post also said to check a service bulletin about 4 stroke pcm ground but I can't seem to find anything on the topic.
<p class="MsoNormal">http://www.marineengine.com/boat-forum/showthread.php?442722-2006-25hp-4-stroke-will-crank-won-t-run</p>
Just looking to see if anyone else has any thoughts on what else the issue could be.
PS: Hope it's not too much info but I didn't want to leave anything out.
Background: I got this pontoon/motor last year and it ran fine up until now. Since I've ran it I've only used 91 octane alcohol free fuel with Star Tron Marine Fuel Treatment. I replaced the old fuel hose from the portable tank to the motor and bulb this year along with replacing the old external fuel/water filter separator.
Background of what happened: Ran the motor for about half hour and then sat in the middle of the lake
for about an hour. Went to go start it and it ran for a second and then died.
After that I tried starting it again and all it would do is turn over. I checked for spark and had spark and check the fuse and it was good. Also checked the battery and it was at 12.6 volts. Eventually was towed in.
Once back I replaced the spark plugs (as a maintenance item), took off the VST and cleaned that and it was really bad (Fuel Pump had rust all over it and was clogging the screen). Hooked the high pressure fuel pump up to a battery to test it and it ran. Put everything back together and still all the engine does is crank.
The next day I checked the fuel pressure rail and there was no pressure. I disconnected the output
on the VST where the pump should be sending fuel into the high pressure side of the system and turned the key and nothing. I then decided to try to jumper the high pressure fuel pump with a small 12v battery. As soon as I connected the little battery fuel sprayed everywhere. Which meant to me that the high pressure fuel pump is good.
I then reconnected the high pressure hose to the VST and then jumpered the high pressure fuel pump to a small battery and the pump ran and a friend turned the key and the engine ran for 15 seconds until I removed the fuel pump jumper wire.
So I’ve narrowed the issue down to I think an electrical issue but I’m not exactly sure as I don’t know enough about boat engines to determine it 100%. Is the high pressure fuel pump tied to anything else to tell it to turn on? Would the pressure regulator valve control the pump at all? I know it opens or something like that when the fuel system is around 40 PSI.
I have the battery right now connected to a charger and its charging and sitting at 12.6 volts still. I read another forum post saying a member had to replace their battery with a similar issue but isn’t 12.6 volts enough? I'm unsure of how old the battery is as I can't find a date code on it but I know it's from Walmart as its an Everstart. I also tried hooking up a jump pack to the motor and it still wouldn't start. I would think with a battery and a jump pack that should be more than enough to eliminate it being a battery issue but maybe not? The post also said to check a service bulletin about 4 stroke pcm ground but I can't seem to find anything on the topic.
<p class="MsoNormal">http://www.marineengine.com/boat-forum/showthread.php?442722-2006-25hp-4-stroke-will-crank-won-t-run</p>
Just looking to see if anyone else has any thoughts on what else the issue could be.
PS: Hope it's not too much info but I didn't want to leave anything out.