2001 seadoo challenger v6 efi throttle, help!!

[Grahamjohnson89]

Hey guys need some help, wondering if it’s maf sensor or tps sensor, or something else, boat starts perfect, idles perfect, but as soon as I throttle up to 2k rpm it chokes out and I have to throttle down, but when I full throttle it kicks right in and runs perfectly fine till I let off just a bit then it chokes out again.... help!! Boat was sitting for two years, I pumped out the fuel and oil and replaced with new stuff still having issues

 

[Tim75]

Hey guys need some help, wondering if it’s maf sensor or tps sensor, or something else, boat starts perfect, idles perfect, but as soon as I throttle up to 2k rpm it chokes out and I have to throttle down, but when I full throttle it kicks right in and runs perfectly fine till I let off just a bit then it chokes out again.... help!! Boat was sitting for two years, I pumped out the fuel and oil and replaced with new stuff still having issues

Could be spark plugs. NGK BPZ8HS -10. Also known as NGK 3133. Price runs from $6 to $28 each. $51 for a box of 10 from RockAuto.com. Post if you find cheaper.

Possible fuel injectors or trigger base. Try plugs first. Easiest and cheapest. Might try fresh gas, too.

 

[Canadian06]

Following. Mine has similar symptoms.
It won’t rev over 1600-1800 rpm. The previous owner installed a toggle switch to bypass the neutral safety switch but i tested it with a multimeter.
I don’t know where to look next.
It has new plugs, and new gas, ran great last year

 

[Tim75]

Following. Mine has similar symptoms.
It won’t rev over 1600-1800 rpm. The previous owner installed a toggle switch to bypass the neutral safety switch but i tested it with a multimeter.
I don’t know where to look next.
It has new plugs, and new gas, ran great last year

Visual check the trigger wires that come out from under the flywheel. 6 wires up to a connector just aft of the flywheel. Merc used crappy wire on the old units that had insulation that would crumble over time (20 years!) and cause many problems. Pretty easy to test in place. Need an ohm meter.

Plugs that were "new last year" are not exactly fresh. My engine went to sleep for winter running perfectly. Ran like crap in spring. Stumbling at 1800rpm. But if I jammed the throttle WOT, it would run 6200rpm. Would not run in between. New plugs and it runs perfectly.

The tps adjusts fuel from about 20% to 80% throttle opening. If tps fails (as they are known to do), ECU makes fuel flow thru injectors full rich. So rich it can "flood" the engine. Very hard to restart. After 30 minutes, it will finally start.

 

[Grahamjohnson89]

Thanks tim75 my spark plugs are on the way, as well as a voltage reader, will be changing plugs then test, if issues still there will be testing tps, I also put one can of sea foam in, hopefully that’s enough cause I know it’s a big tank

Visual check the trigger wires that come out from under the flywheel. 6 wires up to a connector just aft of the flywheel. Merc used crappy wire on the old units that had insulation that would crumble over time (20 years!) and cause many problems. Pretty easy to test in place. Need an ohm meter.

Plugs that were "new last year" are not exactly fresh. My engine went to sleep for winter running perfectly. Ran like crap in spring. Stumbling at 1800rpm. But if I jammed the throttle WOT, it would run 6200rpm. Would not run in between. New plugs and it runs perfectly.

The tps adjusts fuel from about 20% to 80% throttle opening. If tps fails (as they are known to do), ECU makes fuel flow thru injectors full rich. So rich it can "flood" the engine. Very hard to restart. After 30 minutes, it will finally start

 

[Tim75]

Thanks tim75 my spark plugs are on the way, as well as a voltage reader, will be changing plugs then test, if issues still there will be testing tps, I also put one can of sea foam in, hopefully that’s enough cause I know it’s a big tank

Sea foam
Big mistake. It dilutes the already miniscule amount of oil between piston and cylinder and can cause MAJOR issues like piston meltdown.

 

[POPPS]

Shot in the dark, had merc,,,similar type symptoms,,,,replaced he stattor which controls I believe the high low ignition,,,ran like a champ, Also, check for charging therefore, !,,but that does not guarantee the hi lo issue to the coil,,,check for burning wnd discolourization on the 3 yellow charging wires,,,the coupler.,,over time, becomes a hi heat "handshake."