We got our vmaxx running good!! Cleaned the whole fuel system, all screens filter, i jectors & replace mystery filters as well on the HPDI pump & ran good, would let go when going from 30mph to full throttle, but doesnt let go amymore!
We having similar issues, we are gonna test fuel pressure soon, hard to get the boat on plane & it lets go & goes back & forth.. We replaced fuel lines & hand pump so far.
Mine was doing the same thing..was the fuel pump inside the vst not building up pressure. Replaced..no more surging. basket filter design on side of engine not filtering small particles before entering vst. fuel pump in vst not seated properly with cut o ring.
It was a combination of bad Diaphragm-fuel pumps, bad fuel-squeeze-bulb-pump and fuel-hoses from the tank in out case. We replaced all the parts regarding fuel that has a service-interval. Fuel hoses Squeeze-bulb-pump Diaphragm-fuel pumps (All three) VST fuel pump filter We also removed the check-valve since this is not needed. The engine now runs correctly! We still dont get top-rpms, but this is most likely the O2 (lambda) sensor.
We got our vmaxx running good!! Cleaned the whole fuel system, all screens filter, i jectors & replace mystery filters as well on the HPDI pump & ran good, would let go when going from 30mph to full throttle, but doesnt let go amymore!
We having similar issues, we are gonna test fuel pressure soon, hard to get the boat on plane & it lets go & goes back & forth..
We replaced fuel lines & hand pump so far.
Same problem with plane it was fuel pressure regulator
@@beenova3247 our was dirty gas tanks, we had to clean all the fuel filters & screens on injectors.
Thanks still new at this but starting to get it
Mine was doing the same thing..was the fuel pump inside the vst not building up pressure. Replaced..no more surging. basket filter design on side of engine not filtering small particles before entering vst. fuel pump in vst not seated properly with cut o ring.
Did you figure out what the problem was?
It was a combination of bad Diaphragm-fuel pumps, bad fuel-squeeze-bulb-pump and fuel-hoses from the tank in out case.
We replaced all the parts regarding fuel that has a service-interval.
Fuel hoses
Squeeze-bulb-pump
Diaphragm-fuel pumps (All three)
VST fuel pump filter
We also removed the check-valve since this is not needed.
The engine now runs correctly! We still dont get top-rpms, but this is most likely the O2 (lambda) sensor.