kenn6752
07-15-2015, 11:08 AM
Last weekend noticed the boat didn't want to run up over about 1/2 throttle and the rpm's stopped climbing around ~3000. Backed it off and it ran fine around 1/4-1/2 throttle (~2000) for awhile heading back to home. After a bit longer it was losing the power at that speed and continued to weaken down to a rough idle. From there it was sputtering down to very near stall and then would eventually find itself and jump back up to maybe 1500 rpm for a few seconds before leveling back out.
Put a fuel pressure gauge on it last night and it had 29-30 psi at key up prime. Turned it over and it fired up maintaining the 29. Idled out, still running smooth and @ 29psi. Began to run through the throttle and it was reving up smoothly and holding the ~29psi through close to 3/4 throttle. Started to lose its ability to keep climbing in speed/rpm after 3/4 throttle and when I kept pushing it up it started to bog down. Fuel pressure was dropping to 20, then 15, down to under 10psi. Backed off to idle and after a few seconds it recovered to the 29. Ran through again and similar results except it seemed to run out of steam and bog closer to 1/2 throttle. Idled to the dock and it leveled pressure back off. After awhile of looking around and having it idling (in neutral) it started to sputter around and nearly die before spiking the rpms to keep itself going. Not much longer it just gave out and stalled.
Specs:
2004 Assault 325 TBI
Recent Maintenance:
New plugs 2014
New fuel filter 2015
New Cap and Rotor 2015
Fluids 2015
Having to tried to best explain the symptoms above- what is anyone's opinion on what is likely up? I am very strongly leaning to a new fuel pump based on the pressure readings showing it dropping off. I put a dmm on the harness to the pump and it showed ~12v which seemed like good power to it. I just hate to throw $300 at a pump it if truly isn't related.
Is there any way to test the pump? Would it make sense for the pump to clearly turn on and prime to proper pressure, even run well for awhile before starting to have an issue. And then repeat that sequence again a few days later? Also, it will fire back up after a stall/turn off so I don't think it matches vapor lock symptoms, especially since the issue seems most prevalent at higher speeds.
Also- what is the correct pressure for my engine? The service tech mentioned 30psi which made my 29psi make sense. But then I keep seeing talk of 60psi, but I assume that may be for newer models?
Lastly- if the consensus is to get a new pump, are there any recommendations on model, etc.? I have email skidim for a model match, but just wondering. Seems like there would be a cheaper alternative out there with the same specs.
Put a fuel pressure gauge on it last night and it had 29-30 psi at key up prime. Turned it over and it fired up maintaining the 29. Idled out, still running smooth and @ 29psi. Began to run through the throttle and it was reving up smoothly and holding the ~29psi through close to 3/4 throttle. Started to lose its ability to keep climbing in speed/rpm after 3/4 throttle and when I kept pushing it up it started to bog down. Fuel pressure was dropping to 20, then 15, down to under 10psi. Backed off to idle and after a few seconds it recovered to the 29. Ran through again and similar results except it seemed to run out of steam and bog closer to 1/2 throttle. Idled to the dock and it leveled pressure back off. After awhile of looking around and having it idling (in neutral) it started to sputter around and nearly die before spiking the rpms to keep itself going. Not much longer it just gave out and stalled.
Specs:
2004 Assault 325 TBI
Recent Maintenance:
New plugs 2014
New fuel filter 2015
New Cap and Rotor 2015
Fluids 2015
Having to tried to best explain the symptoms above- what is anyone's opinion on what is likely up? I am very strongly leaning to a new fuel pump based on the pressure readings showing it dropping off. I put a dmm on the harness to the pump and it showed ~12v which seemed like good power to it. I just hate to throw $300 at a pump it if truly isn't related.
Is there any way to test the pump? Would it make sense for the pump to clearly turn on and prime to proper pressure, even run well for awhile before starting to have an issue. And then repeat that sequence again a few days later? Also, it will fire back up after a stall/turn off so I don't think it matches vapor lock symptoms, especially since the issue seems most prevalent at higher speeds.
Also- what is the correct pressure for my engine? The service tech mentioned 30psi which made my 29psi make sense. But then I keep seeing talk of 60psi, but I assume that may be for newer models?
Lastly- if the consensus is to get a new pump, are there any recommendations on model, etc.? I have email skidim for a model match, but just wondering. Seems like there would be a cheaper alternative out there with the same specs.