Throttle issue for a Avalanche C4

[CenturionReVolution 0]

I have a 2009 Avalanche C4.  I'm currently experiencing an issue where the motor is non-responsive to the throttle unless I give it full throttle.  The motor does not stall out and idle's fine and does not have a misfire and does not die at any point through the process.  

When the throttle is pushed forward the boat takes off.  However within 2-3 seconds the power cuts back and boat idle's back down even with the throttle engaged.  When it does this during the 2-3 seconds the motor idles up it also engages the prop.  However as soon as the motor idles down the prop also disengages.  

If I throttle the boat all the way up the boat will take off and run at top speed.  However any throttle position other than wide open the boat will not raise the RPM's and does not engage the prop other than maybe the first 2-3 seconds.  After that the prop is no longer engaged and the RPM drops down to idle speed around 800-1000 RPM.  

Has anyone had any experience with something similar to this?  This issue did not exist last year prior to winterization and is something completely new.  The only thing that we have had done to the boat new for this season is we had a new amp installed and head unit installed for the stereo system.  Outside of that the boat is exactly the same as last fall when we pulled it out of the water. 

Thanks in advance for any guidance here. 

[CenturionReVolution 0]

I also wanted to mention that the red warning light on the dash is on.  The boat was completely serviced prior to putting it in the water. 

[Troy 234]

Check distributor. Might have corrosion inside.  Or maybe IAC? 

[rhino89523 34]

Weird, kind of sounds like 2 issues ...something isn't right or I don't understand. The tranny is either in or out to my understanding. You roll the throttle forward and you can feel where it catches the gear....thats that, after that speed is just a function of rpm's. If it is falling out of gear that is one problem and your motor run condition is another.

so when you hold it at say half throttle, it throttles up and launches forward, then 2 to 3 seconds later it throttles down....at this point it is neutral just floating in the water no steering no nothing? If thats the case for starters I would be looking at the tranny.

My other thought is maybe when they tied in the head unit somehow they grabbed some of the prefect pass wiring...total long shot but when I take off and forget to turn off the perfect pass that is about the time it takes before the  perfect pass tries to take over operation, I have to go back...put it in neutral and wait for it to wind in while everyone on the boat says "You forgot again" maybe a few too many hits to the head.     

[InfinitySurf 302]

Have you checked tranny & v-drive fluids and would it do that if fluid is low and light is on?

[CenturionReVolution 0]

Do any of you know where to check the V-Drive Fluid... Sorry that may be a stupid question but I honestly cannot figure out where to check it from. 

 

[InfinitySurf 302]

If you are in the boat and looking back at the engine....  you will first see the v-drive unit and then directly behind it is the transmission (in this pic the vdrive is at bottom center.... then you can see the yellow dipstick to the trans behind it.

(there should be a plate/tag on both of them telling you the brand, model and ratio).

This is the vdrive 

 

This is the transmission 

Some boats have an access hole under the rear seat that is the easiest way to check the fluids for them both. On some boats both the v-drive and the transmission have a dipstick, On some v-drives you have a small "plug" instead of a dipstick (this is how my model is). Look at your manual since different models have a different process to looking at fluid levels and are checked differently. Mine for instance on the trans, you check it cold and remove the dipstick and wipe it....then you put dipstick back in but do not screw it down to check the level.