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iliketoski

Low RPMs, Not good top end

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iliketoski

A buddy got a new to him 23' LSV (2002 0r 3) monsoon, 330. He got a deal on it, been stored in a garage about 150 hours on it. First he replaced the fuel, then again after finding water in the new tank (the vent was turned upward). Anyway, new plugs, new wires, new cap, he says he put a fuel separator on it, because it didn't have one, (which I find hard to believe).

Anyway only getting 3600 RPM, and speed in the mid 30's. No misses or anything, Prop looks ok, but not professionally checked. Not throwing any codes, fuel pump pressure (at pump) is upper 40's

I recommended looking for fuel filter, (my 2001 VLX monsoon has an inline and one on the motor). I couldn't find an inline one near the tank like mine. I also recommended fuel injector cleaning, but it seems it would be missing if that far off top RPM. A local marine mechanic, (not Malibu specific) says its the computer. I doubt that.

Any suggestions on where to go next?

Edited by iliketoski

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85 Barefoot

what prop is on it?

from what is he getting his RPM reading? just the analog tach or does perfect pass confirm?

Edited by 85 Barefoot

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MadMan

A couple more things to check, ignition timing, and is the throttle opening completely? Does it get above 3600 rpm out of gear?

It could still have a bad sensor (even with no codes). A trick to identify a sensor that is giving a valid reading, but is wrong, is to unplug the sensors (TPS, MAP, knock, temp) one at a time. The MEFI will go to a default reading for that sensor, if the performance improves, it points to a bad sensor.

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Bozboat

A buddy got a new to him 23' LSV (2002 0r 3) monsoon, 330. He got a deal on it, been stored in a garage about 150 hours on it. First he replaced the fuel, then again after finding water in the new tank (the vent was turned upward). Anyway, new plugs, new wires, new cap, he says he put a fuel separator on it, because it didn't have one, (which I find hard to believe).

Anyway only getting 3600 RPM, and speed in the mid 30's. No misses or anything, Prop looks ok, but not professionally checked. Not throwing any codes, fuel pump pressure (at pump) is upper 40's

I recommended looking for fuel filter, (my 2001 VLX monsoon has an inline and one on the motor). I couldn't find an inline one near the tank like mine. I also recommended fuel injector cleaning, but it seems it would be missing if that far off top RPM. A local marine mechanic, (not Malibu specific) says its the computer. I doubt that.

Any suggestions on where to go next?

.

Same problem, for me having the fuel injectors cleaned and mapped fixed it. I had a few other problems pop up, but my original problem was the boat would not run past 3800 rpms or so.

http://www.themalibucrew.com/forums/index.php?/topic/57029-fuel-injectors-cleaned/?fromsearch=1

Edited by Bozboat

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grandude

I agree it's likely the injectors. When people suggest cleaning fuel injectors it's not running a $7.95 can of injector cleaner thru the gas. They need to be removed and professionally cleaned. It's not that hard to do. There are multiple injector cleaning services available online. Most do a pre cleaning leak test as well as spray pattern and flow rate analysis. Often they do a screen shot of pre cleaning spray pattern and post cleaning pattern. I have often seen injectors that looked like they had been scooped into the dirt on the input side of the first couple of injectors coming into the fuel rail. Low RPM or slow acceleration are typical issues.

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SmoothWaterMan

Do a power balance test under load and make sure all cylinders drop.

Peter

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iliketoski

Couple comments, (Thanks for responses so far)

  • Not sure on prop, 4 blade one that came standard
  • History shows much higher RPM
  • Yes off RPM read off analog gauge no PP, speed and RPM are just not getting there
  • What is a power balance test?

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ibelonginprison

1. replace the fuel filter.

2. if you can't find a fuel filter (as in it doesn't have one) then I'm guessing we know why the injectors are clogged and need to be sent off to be cleaned. lol

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iliketoski

IT seems had to believe the setup is that different than my 01 VLX, Could they really not put a filter in from the factory?

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