2004 EFI Mercury 4 stroke

[Tsengel]

I have been having problems with my outboard cutting out and not shutting off, the guy has replaced the battery ( thinking low voltage) Then he replaced the wire harness inside the motor (thinking improper connections) Now they want to replace the CPU on the motor, not sure what cable controls that, they said when they wiggle one cable going to the motor then the motor revs up again.

Does anyone know what cable are they talking about?

 

[Timestep]

Re: 2004 EFI Mercury 4 stroke

What did thier diagnostic computer indicate as the fault??

Dave

 

[Vanover]

Re: 2004 EFI Mercury 4 stroke

Yeah being a 2004 you should get something as a fault. This will help everyone help you.

 

[Tsengel]

Re: 2004 EFI Mercury 4 stroke

Yeah being a 2004 you should get something as a fault. This will help everyone help you.

It gave them a low voltage fault that led them to the battery the first time. Now they said when they take it out and they wiggle a cable to the computer part then they can make the motor run fine.

 

[nicknight]

Re: 2004 EFI Mercury 4 stroke

I am not a boat mechanic but I suspect the mechanics are jerking you around OR Someone please correct me if I am wrong:

Motors don't need batteries to continue running. They need an alternator. You can disconnect your battery and the motor would run fine.

So if this is the case I would be complaining to the shop and/or go elsewhere. It also sounds like they do not have the tools to properly diagnose issues on your motor (no mention of a comp readout) take your boat somewhere else.

also not shutting off.....does this mean that it keeps going until you starve it of fuel or is it desiling?
A motor requiring a battery to turn off? I am thinking that there is no way this would be allowed since it is unsafe.

nn

 

[SparkieBoat]

Re: 2004 EFI Mercury 4 stroke

the not shutting off problem could be connected with the cutting out issue, on my 03 yammy F115 which is the exact same motor as you have, my ISC valve was sticking, causing my ECU to over heat and freaking out the electronics, tach was freaking out, engine would not shut off for several seconds to a minuet after I shut off key switch. I am running ok now, hoping there is no permanent damage to ecu. I soaked my ISC valve in sea foam for 2 days, it started working again. Also replace every filter, clean out VST chamber and screen on bottom of high pressure fuel pump, also recommend sending off injectors for cleaning/flow test. parts for these motors are ridiculous stupid high. after every thing I listed above my motor now runs like a champ. you can tell if the isc valve is stuck by feeling it, if it is sticking it will get pretty hot after just a few minuets of idling.

 

[Tsengel]

Re: 2004 EFI Mercury 4 stroke

Thanks for the input, I will see what I can find out and have my mechanic look at it and check it out.

 

[Tsengel]

Re: 2004 EFI Mercury 4 stroke

FYI, SparkieBoat ended up hitting the nail on the head, they did put a new ECU on and it still had the idling problems, I suggested the part that Sparkie Said the Idle Control Valve and the mechanic said it ran like a champ after that. Wish Sparkie lived a little closer it would have been alot cheaper for me.

The mechanic was surprised when this ended up being the fix, thanks Sparkie