Ok so this is what in working with and thanks in advance to anyone who can shed some light on this one..
2006 2.5L 150hp optimax
1095 hours
Start of the problem:
Engine runs for about 45 min. After around 45, the engine slowly looses RPM. When this happens it will only get around 3000 RPM. Feels like it either lost a cylinder or starving for fuel. Problem gets worse the longer you drive it. Gets to the point when you cannot start the machine. Fuel pressure was at 90 PSI ( however the needle bounces very rapidly ) and air pressure at 80 PSI. Let it sit and cool down and repeat exact same scenario.
Inspected plugs. Replaced. IZFR5G
Tested Batteries, cables, harness. Ran test set of cables, and used my shop harness.
Ran with timing light on all 6 high tension lead. 2 seamed weaker than the rest so I swapped out the drivers and the coils just so i could eliminate electrical
Engine is not overheating and no alarms
quick test and still same exact scenario
So I got my test fuel tank to run a quick test and bypass the boat fuel tank. Undid the harness and disconnected the fuel line which is when I noticed this boat has the old style merc fuel line with the red writing. At that point I saw the writing on the wall. I jumped off the end of the warf and started swimming hoping something would run me over. What really happened is i noticed what looks like the lining in this line has flaked off into tiny pieces. For the hell of it I tried my gas but nada. So this is what i did
Took off the VST filter. Completely jammed with this material. took off the VST. open her up. and surprisingly no signs of any debris. the filer has done its job. took off the diaphragm style lift pump. the one between the tank and the electric low pressure pump. only to find a couple small pieces of debris. Looked good actually. Reinstalled the assembly after cleaning and reassembling etc etc. Now the problem gets worse.
Testing in the water with 2 new filters, fuel line, cleaned out VST, Lift Pump, both electric pumps, and all lines. Using my gas, new plugs, and my harness. Same problem just happens after about 10 min now. Then won't even idle. Checking fuel pressure now I'm only getting 80 PSI on the fuel and on the air.
Hmmm. So i pulled the regulator and the tracker diaphram on the port and starboard fuel rail. Looked fine. Inspected for holes tiny pinholes. Look minty. Reinstalled. Pulled the Air regulator on the port side. Screen was almost fully clogged with small debris. Cleaned it and reinstalled it. Tried to run it again and now the problem is even worse. Still 10 PSI low on pressure. Manually tested and verified all pumps are getting power. Manually triggered while running. No pressure change. Replaced both low and high pressure electronic pumps. This is where it gets interesting.
After new pumps installed.
Primed fuel system
New pumps sounds a lot quieter
Verified they worked manually
Getting voltage while key on and cranking
Now only getting 70 PSI. WTF. I took the tracker valve back apart to double check it. Looks minty. Verified that it has zero leaks and is water tight. Verified that i did not install it incorrectly. reinstalled it. Now I'm getting pressure and bam starts up and runs beautiful. Ran it tied to the dock up to about 2500 RPM for about 10 min. Untied the boat and dies about 100 yards from the slip. Didn't even make it out of the marina. Trying to start it and fuel pressure is at 70PSI. Got back to the dock. took the injectors out, diaphrams, the whole assembly. Did not see any orings torn, or any kind of signs of debris or carbon..nada. Measured impedance and voltage on all injectors and sensors. All perfect. Reinstalled. Wont start at all now. Warm or cold.
Fuel pressure looses pressure slowly after cranking and testing pressure. Air pressure still 80PSI.
What am I missing?
Stuck open injector?
Seth
2006 2.5L 150hp optimax
1095 hours
Start of the problem:
Engine runs for about 45 min. After around 45, the engine slowly looses RPM. When this happens it will only get around 3000 RPM. Feels like it either lost a cylinder or starving for fuel. Problem gets worse the longer you drive it. Gets to the point when you cannot start the machine. Fuel pressure was at 90 PSI ( however the needle bounces very rapidly ) and air pressure at 80 PSI. Let it sit and cool down and repeat exact same scenario.
Inspected plugs. Replaced. IZFR5G
Tested Batteries, cables, harness. Ran test set of cables, and used my shop harness.
Ran with timing light on all 6 high tension lead. 2 seamed weaker than the rest so I swapped out the drivers and the coils just so i could eliminate electrical
Engine is not overheating and no alarms
quick test and still same exact scenario
So I got my test fuel tank to run a quick test and bypass the boat fuel tank. Undid the harness and disconnected the fuel line which is when I noticed this boat has the old style merc fuel line with the red writing. At that point I saw the writing on the wall. I jumped off the end of the warf and started swimming hoping something would run me over. What really happened is i noticed what looks like the lining in this line has flaked off into tiny pieces. For the hell of it I tried my gas but nada. So this is what i did
Took off the VST filter. Completely jammed with this material. took off the VST. open her up. and surprisingly no signs of any debris. the filer has done its job. took off the diaphragm style lift pump. the one between the tank and the electric low pressure pump. only to find a couple small pieces of debris. Looked good actually. Reinstalled the assembly after cleaning and reassembling etc etc. Now the problem gets worse.
Testing in the water with 2 new filters, fuel line, cleaned out VST, Lift Pump, both electric pumps, and all lines. Using my gas, new plugs, and my harness. Same problem just happens after about 10 min now. Then won't even idle. Checking fuel pressure now I'm only getting 80 PSI on the fuel and on the air.
Hmmm. So i pulled the regulator and the tracker diaphram on the port and starboard fuel rail. Looked fine. Inspected for holes tiny pinholes. Look minty. Reinstalled. Pulled the Air regulator on the port side. Screen was almost fully clogged with small debris. Cleaned it and reinstalled it. Tried to run it again and now the problem is even worse. Still 10 PSI low on pressure. Manually tested and verified all pumps are getting power. Manually triggered while running. No pressure change. Replaced both low and high pressure electronic pumps. This is where it gets interesting.
After new pumps installed.
Primed fuel system
New pumps sounds a lot quieter
Verified they worked manually
Getting voltage while key on and cranking
Now only getting 70 PSI. WTF. I took the tracker valve back apart to double check it. Looks minty. Verified that it has zero leaks and is water tight. Verified that i did not install it incorrectly. reinstalled it. Now I'm getting pressure and bam starts up and runs beautiful. Ran it tied to the dock up to about 2500 RPM for about 10 min. Untied the boat and dies about 100 yards from the slip. Didn't even make it out of the marina. Trying to start it and fuel pressure is at 70PSI. Got back to the dock. took the injectors out, diaphrams, the whole assembly. Did not see any orings torn, or any kind of signs of debris or carbon..nada. Measured impedance and voltage on all injectors and sensors. All perfect. Reinstalled. Wont start at all now. Warm or cold.
Fuel pressure looses pressure slowly after cranking and testing pressure. Air pressure still 80PSI.
What am I missing?
Stuck open injector?
Seth
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