5.7 OSXI-G Suddenly died on me

[Northerpearl]

Hi,

Just the other day I was out on the water. I had just left the dock I think I got 7 minutes out before the engine suddenly died. I did not succeed to get it started again. I then noticed that the temperature gauge for the engine was at its peak level but the engine was not that warm, I could tuch it with my hand. Now 5 days later the gauge for the temperature still shows max temp and the oil pressure gauge shows almost 40 psi even thoug the engine is not running.

I can hear the fulepumpe prime as I turn the key so that is at least functioning. So I guess this is a electrical issue based on the false reading on the gauges?

Any ideas where to start my troubleshooting?

BR
Ola

 

[alldodge]

Going to need the engine serial number

Start with the basics, check fuses on the motor and boat. Use a voltmeter and see if there is 12V at the motor when key is ON.

Is this a new to you boat?
muc

 

[Northerpearl]

Thank you for your answer.

The engine serial number is 4012193473, it is a 5.7 OSXI-G engine. The motor has 12V at the starter at least since it cranks but is does not fire up. This is the first time this happens to me and I have owned the boat for 1 year. I have also checked the fuel pump rele and this works. I have not checkd the fuel pressure or flow but this happend suddenly and there was no rough running prior to this insident.

 

[alldodge]

Sorry, my comment wasn't clear
I'm looking to see if there is 12V at the ignition components on the motor like the coil

With the serial number I see you have the flat distributor cap which is known to fail without warning, and most replace just to keep a spare. That said, with the temp gauge pegged and oil gauge at 40 without the motor running is of concern.

Assuming the gauges stay at zero with key OFF, and only show readings when key is ON?

When cranking does the tachometer show any movement?

 

[Northerpearl]

I need to check at the coil, should there be 12V at the coil with the key in ON possition or do I need to crank?

Okay, is there any way of checking this component? Will this result in the spark not going from the cap to the spark plug?

When the key is in off possition all the gauges are at "zero", when I turn the key on to ON possition the gauges give the false reading. I can see that the tacometer makes small "jumps" at the lower range of the tachometer when I try to crank.

Thank you for the follow up!

 

[Northerpearl]

Just some pictures of the gauges. This is with the key in ON possition but without the engine running.

 

[alldodge]

Not positive, but I think the gauges are readings from the ECM (digital) and are not analog. If this is the case then the ECM may have gone out, or there is a voltage issue which is corrupting the readings.

Need to get the motor scanned for codes

 

[Northerpearl]

So if I disconnet the ECM, turn on the power and turn the key to ON there shold be no reading on the gauges if they are controlled by the ECM? The local boat repair shop are fully booked until the end of july so I hope to do som pelimenary checks in advance. Is there any way to check if there is sufficient power to the ECM, do it get both ground and power through the loom or is the ground the connection to the riser?

 

[alldodge]

If ECM is disconnected and the gauges stay at zero then it would assume they are controlled by it.

Power and ground to the ECM comes thru the motor wiring harness. Don't know if your motor gets power by energizing a main relay or it comes direct from the key switch. In any case the key does turn it ON

 

[Northerpearl]

Thank you, then I will try to disconnect the ECM to check it the gauges are digtal on analog.

I guess there are a lot of different setups (I have a Reagal 2750 Cuddy 2008), but is there a fuse that could be blown that prevent the ECM from switching on or is the ECM trash if it is shown that the ECM is the cause for the false readings? Just had a google on the ECM and this is a 2000 dollar part so I hope this is not burnt.

 

[alldodge]

There are a few fuses and/or breakers on the motor, checking them first. I would think that if a fuse blew it would have no connection but then again I don't have a wiring diagram to look at

 

[Northerpearl]

So I unpluged the wiring harness from the ECM and both the oil pressure gauge and the temp gauge gave no reading. So therfore the sensors are wired to the ECM and from the ECM to the gauges. It is therfore reason to beleve that the ECM is the issue. This could also explain why the motor suddenly without warning did stop. IS there any way of checking for error codes or some way to test if the ECM is broken or if there are some interference that could trigger this without using diagnostic equipment?

The ECM that is in my boat has a VP number 3885457. Is there any way of replacing this without buying a new one? Possible to repair og by another product?

 

[alldodge]

Wish I had better idea, I don't know anyone who can repair them, and maybe only VP dealer can test. If muc doesn't have an idea a dealer is about all there is left