21i problem

[pklakeguy]

I just bought a new 2007 21i with the 340 hp vortec engine. I took it out for the first time last weekend and loved it, but had 1 problem. About 5 or 6 times that day the engine would start cutting out when accelerating. It could best be described as sputtering and popping (like backfiring) and had no power. I tried giving more throttle and I tried giving less throttle and neither worked. I would have to put it in neutral and start over. It had about 3/4 of a tank of fresh fuel. Anyone have this happen to them? I'm hoping its an easy fix because the dealership I bought it from is nowhere close and they don't really know what is going on. Any help would be much appreciated!

[FIC]

It sounds like fuel starvation , but before you go there first get under the dash and make sure the wires are not loose on the back of the key switch. Next locate the fuel pumps and check the wires on the bottom of the low preassure pump thats the smaller pump and the lowest one on the front of the motor.

[dogbert]

You might also want to make sure the fuel vent is not obstructed. If the boat sat for that long, maybe something got in there and built a nest, blocking off the air flow into the vent.

[Hacksaw]

I feel your pain. I have a 2007 20v with the Marine Power motor that had similar symptoms to what you describe. Eventually we traced the problem to the engine controller software.

Unlike my 96 Pre2000wt this new boat, and I believe all 07s ,are throttle by wire. For some reason early software versions looked for a speed signal even when not using SPEEDSET. This was confirmed when I forgot to take the tape off the paddle wheel after towing and the boat stopped responding to the throttle completely and would just idle around.

We fixed the boat by getting the latest software patch e-mailed to the dealer, who then uploaded the software into the engine controller via a laptop and interface cable. Not only did it fix the throttle issue it improved the responsiveness of the SPEEDSET.

If that had not worked then the next step was to go after a potentiometer in the throttle itself.

My recommendation is to get to a dealer that has the computer interface, check fault codes and software versions that are resident, then upload the new version. Best if you can do this on the lake as I did with my dealer. After we accomplished the load we tested the boat with the laptop plugged in to capture data and monitor engine performance parameters real time.

Hope this helps.