IAC Help?
 

Have 08 with 525, been trying to get this boat to run right all this year with no luck. Now I'm wondering about the IAC, when you throttle up from idle shouldn't the IAC duty cycle come up right away? At idle we are around the 40% and full throttle the engine basically stalls at 2300 rpm for 5 seconds. The IAC duty cycle stays at 40% until it the engine kicks in and the duty cycle goes up with the rpm. Our WOT rpm is also down about 400 rpm. The duty cycle does come up to 98%at 4000 rpms. We have no codes either. Suggestions please!

put a fuel gage on,,,and check fuel pressure under load,,,

The IAC will typically cause the engine not to idle, and die. It will not effect the WOT, I am down on speed also.
I think the government is jacking with the fuel, and the heat is up. I am down a couple MPH myself but everyone else I am running with is down on speed also.

Fuel pressure is good underload, right at 38-42 psi.