HELP PLEASE2010 Sundancer 240 Mercruiser 5.0 MPI

[Fabian Soto]

2010 Sundancer 240 Mercruiser 5.0 MPI

After 6 months no using my boat last weekend when I was running this happened
Boat was running perfect no problems just those beeping noise, also had issues to torn on the motor in neutral always had to Foward a little bit

Engine Misfire code 71
Oxígen sensor code 34

I did a tuned up change
spark plugs
2 gas filter
Also injectors were really bad I cleaned them. also empty the hole gas tank and put new gas

codes didn’t disappears still there I turn on the boat in house for maybe 15 min and reset the system from the clock were have MODE systems
At this point I don’t now what to do have friends that say that kind of motor need a computer to delete those codes
Another version is that when I put the bot on the water again maybe after 20
Min codes disappears
Another version is remove positive from battery
Please someone that can help me with this will be really appreciated
Please check the link for more reference

https://drive.google.com/file/d/1-YlsrykAPT0qx7M5r2ZsAyPXDI5rSnKI/view?usp=drivesdk

 

[Loyd Dinneen]

How old is your fuel? You might add some seafoam to the fuel to clean the system up.

 

[ocgrant]

1. when you say cleaned the injectors what do you mean? Professionally or just wiped them off?
2. did you run it under load since you did all this or just on the trailer?
3. have you done a compression and leak down test yet? This will tell you a lot before you throw parts at it
4. what did the plugs look like?

 

[Fabian Soto]

How old is your fuel? You might add some seafoam to the fuel to clean the system up.

Trust me do not use sea foam never I see results and sea foam and the blue additive it’s really bad find k100’thats the best additive

 

[Fabian Soto]

1. when you say cleaned the injectors what do you mean? Professionally or just wiped them off?
2. did you run it under load since you did all this or just on the trailer?
3. have you done a compression and leak down test yet? This will tell you a lot before you throw parts at it
4. what did the plugs look like?

1- Professionally with the machine also the tank same people did a washout really good results
2 run on the trailer
3 not yet
4 plugs not bad at all

 

[Lazy Daze]

O2 sensor... do you have a catalytic engine?

What type of "beeping noise"? Single beep every so often, 2 beeps every minute, continuous?

Not being able to start the engine without advancing the throttle... the most common cause of that is a failing IAC (Idle Air Controller). It's right on top of the engine.

 

[Fabian Soto]

Yes catalytic engine
Single beep often
Yes IAC is on top