I have a 2008 new to me boat with with a Merc 5.0L MPI with Alpha 1 Gen 2 outdrive with only (61 hours when purchased) 72 hours on it that I purchased last year. The boat ran great all year with issues but I decided to have a bunch of work done on the boat this winter as "preventive" maintenance and for my peace of mind to bring the boat up to my standards. Here is a list of work that was done:
Gimbal Bearing replaced
All bellows replaced
Trim sender/limiter switches replaced
All Spark plugs replaced
tune up done
IAC & Filter replaced
upper and lower shift cables replaced
Water pump replaced
I took the boat out for the first time and had a number of issues that were not problems when the boat was put away. The main problem is typical of what an IAC problem looks like. The boat won't start when cold in Neutral and has to have the throttle advanced in order to start. Once the engine is at operating temperature it is fine. This is presenting as a classic IAC failure but the unit is brand new? I had the mechanic come out on the water and hooked his computer up to the engine and he is unable to override the opening of the valve with the computer. He then replaced the IAC with a second time with a second OEM IAC and the same problem occurred. As we were running the boat he noticed that the IAC got really hot...Unable to touch it hot.
Has anyone experienced anything like this? What are the chances that 2 OEM IAC valves out of the packaging would be bad?
Mechanic said that the IAC isn't throwing an error code, no beeps/tone and no error messages on the digital display on the dash. When the motor was running mechanic pulled the plug on the IAC and immediately got an error code on the computer he had plugged in and an audible signal from the dash.
Mechanic is thinking the ECM might be bad, but with it throwing error codes up it seems like the ECM is sensing things properly. Also the fact that the IAC got so hot it seems like it is trying to open/close/move but unable to which is why heat is building up. Also once running the boat is not idling smooth. it is almost surging (revving up and down maybe a 500-800 RPM surge. This was also a new issue
I am looking for any suggestions on where to start to remedy this issue. Wondering if it is a combination of things that are occurring between the shift cables being out of adjustment and the IAC. Thoughts....????
Gimbal Bearing replaced
All bellows replaced
Trim sender/limiter switches replaced
All Spark plugs replaced
tune up done
IAC & Filter replaced
upper and lower shift cables replaced
Water pump replaced
I took the boat out for the first time and had a number of issues that were not problems when the boat was put away. The main problem is typical of what an IAC problem looks like. The boat won't start when cold in Neutral and has to have the throttle advanced in order to start. Once the engine is at operating temperature it is fine. This is presenting as a classic IAC failure but the unit is brand new? I had the mechanic come out on the water and hooked his computer up to the engine and he is unable to override the opening of the valve with the computer. He then replaced the IAC with a second time with a second OEM IAC and the same problem occurred. As we were running the boat he noticed that the IAC got really hot...Unable to touch it hot.
Has anyone experienced anything like this? What are the chances that 2 OEM IAC valves out of the packaging would be bad?
Mechanic said that the IAC isn't throwing an error code, no beeps/tone and no error messages on the digital display on the dash. When the motor was running mechanic pulled the plug on the IAC and immediately got an error code on the computer he had plugged in and an audible signal from the dash.
Mechanic is thinking the ECM might be bad, but with it throwing error codes up it seems like the ECM is sensing things properly. Also the fact that the IAC got so hot it seems like it is trying to open/close/move but unable to which is why heat is building up. Also once running the boat is not idling smooth. it is almost surging (revving up and down maybe a 500-800 RPM surge. This was also a new issue
I am looking for any suggestions on where to start to remedy this issue. Wondering if it is a combination of things that are occurring between the shift cables being out of adjustment and the IAC. Thoughts....????