Help! Burned up 2 Mefi-4’s on a 2002 5.7 volvo penta Gxi last year

[Porkenchop]

I need help, I have a 02’ 5.7 gxi I burned one ecu up and bought another that was remanufactured, I thought I had found a loose disconnected ground and fixed it. Plugged in the new ecu and the boat ran great for 4 hours. Dropped throttle when coming off plane, the motor died and would not restart. We plugged in diagnostic tool and the ecu would not read. I sent it to Bob at Mefiburn an d he confirmed the second module was toast. I bought another off EBay and had him re program it. I tested it on my port (good engine) and it works fine. Spring is here and I’m ready to get her in the water, but I dont want to plug another $1500 ecu into a harness that will fry it. Any advise on how to diagnose/ and fix this issue would be greatly appreciated as i would like to get more than 4 hours of boating in this year. I’m having trouble finding someone to work on this and really could use any advice! TIA

 

[Shlbyntro]

Its generally a loose/intermittent ground that causes this issue. Almost always.

That being said I had one incident where it was a bad alternator charging at 20v.

Beyond that, it may be time to pin out/replace the harness

 

[Porkenchop]

I really appreciate that, thank you I’m going to go back through the grounds and have the alternator tested. This has been a very frustrating problem, makes me want to go back to a carburetor thank you

 

[Lavey 29]

Possible ecm is repairable. There is many engine sides / voltage sides and even owner bad habits that can cause ecm failures over and over again. If you need help one can reach out in PM. There is only one place that actually offers a possible internal repair and its not in CA either.

 

[Porkenchop]

Possible ecm is repairable. There is many engine sides / voltage sides and even owner bad habits that can cause ecm failures over and over again. If you need help one can reach out in PM. There is only one place that actually offers a possible repair and its not is CA.

Thank you much appreciated. I used mefi burn he reprogrammed one for me and I’m fairly confident the first was rebuilt I’m not sure. i also have seen that Volvo has diodes in their harnesses that can go bad so I’m thinking i need to check every possible cause at this point.

 

[DaveH]

i make mefi replacment harnesses all the time for your situation.....a bad harness that cooked the controller. you need a new harness.

 

[Porkenchop]

i make mefi replacment harnesses all the time for your situation.....a bad harness that cooked the controller. you need a new harness.

Ok, can you send me your information and we can set something up?

 

[DaveH]

Ok, can you send me your information and we can set something up?

PM sent