Stalling or Hesitating under load

[HowNowInJax]

the boat has not running well at all. when applying throttle, the boat hesitates and bogs down only getting to a max of 3000 rpms.
engine is 2008 volvo pennta 4.3 gxi-j

i have replaced fuel filter and MAP

i have scanned with a rinda diacom and i have been looking at the data but i am not getting and clear clue.
i do have faults.. but i think these have been there for a while. because the ECT was thrown and was a bad coolant impeller.. this was also replaced.

SPN: 108 - Barometric Pressure
SPN: 110 - ECT Sensor Fault (appears twice)
SPN: 636 - Crank Sensor Fault

i was going to change the crank sensor, but after searching for hours, i can not find where or what the part is for that on my gxi-j.

i did see an interesting sensor data called "Octane rating" this was a percentage and it fluctuated a lot.. so i thought that was odd.
but the fuel is new and always use non-ethanol..

any other thoughts?
thanks

 

[Scott Danforth]

crank sensor is under the crank on the front timing cover. pointed almost straight down



verify your fuel pressure
verify good ground cables

 

[kmarine]

Just curious... did You check fuel for water when installing filter?

 

[HowNowInJax]

crank sensor is under the crank on the front timing cover. pointed almost straight down



verify your fuel pressure
verify good ground cables

thanks, i will go look under there and see if i can get a part number and picture.

i will also look at the fuel pressure and grounds.
looking at the scanner output, any voltage logged looked stable.. but i am not sure if that is enough to rule out ground issues.

 

[HowNowInJax]

Just curious... did You check fuel for water when installing filter?

i did not, as it start leaking a bunch of gas and was not prepared for that and quickly through it to the side to get the new one on.. next time i can be ready for the extra gas.. what in the filter would i be looking for?

 

[HowNowInJax]

i got a picture of the crank position sensor. but.. i cant seem to upload the image here in the forum.
searching for the part has been really hard.. only ones come up are 2007 and older.. why is finding these for a 2008 and newer so hard?

 

[Scott Danforth]

thanks, i will go look under there and see if i can get a part number and picture.

its a generic GM crank sensor for 1996 and newer 4.3/5.0/5.7 motors. if you look in the electrical forum stickies, I have the generic sensor catalogs there. either SMP or littlefuse will have it.

i got a picture of the crank position sensor. but.. i cant seem to upload the image here in the forum.
searching for the part has been really hard.. only ones come up are 2007 and older.. why is finding these for a 2008 and newer so hard?

we are having server issues that are keeping us from loading pictures currenlty

 

[Scott Danforth]

you can look here https://forums.iboats.com/threads/generic-boat-wiring-information-updated-verified.726970/

at post #12

at link #3 or link #4

 

[cyclops222]

New correct sparkplugs ? When was last change ?

 

[BRICH1260]

I`d check plugs and distributor cap and rotor. Also plug wires. Replace all if not done in last few years.

 

[HowNowInJax]

New correct sparkplugs ? When was last chaplug and wires are a few years old.. i will pull the plugs next to see how they look.

New correct sparkplugs ? When was last change ?

Plugs and wires were changed a few years ago.. i will pull them and look at them next

 

[HowNowInJax]

New correct sparkplugs ? When was last change ?

a few years ago

 

[HowNowInJax]

Fuel pressure is good, 50-55 lbs.... also, stable under rev. next is looking at the plugs.

 

[HowNowInJax]

inspecting my plugs, they are not steamed, so i think i can rule out water in the gas...
while i hade them out, i did test the plugs and i had a failed plug..
so i have some new plugs on the way.. fingers crossed that is the only issue..

 

[cyclops222]

Not all bad plugs can be seen as bad. The shorting out a plug test is very accurate. Especially if a lot of plugs are erratic in their firing patterns.

 

[BRICH1260]

Pull your distributor cap and look underneath at the contacts of it and the rotor. They go bad quickly.

 

[alldodge]

looking at the scanner output, any voltage logged looked stable.. but i am not sure if that is enough to rule out ground issues.

What voltages are you seeing, and is 5V exactly 5V ?