MEFI 3 to MEFI 4 conversion

[britandy]

Quick question, I am converting from MEFI 3 to MEFI 4 on my 7.4 Mercruiser, as the original ECU died. I have the conversion kit from OBD Diagnostics. However it did not come with any install instructions. It is fairly obvious but just one thing I am not sure of. Do you have to plug the 10 pin (male) connector that comes with the conversion harness into the MEFI 3 diagnostic connector (female)? The engine does run without connecting it, but then why is it there?

 

[britandy]

OK, so I am going to answer my own question, OBD Diagnostics did just get back to me and said in my application I do not plug it in.

 

[scoflaw]

Curious, what was the cost of that conversion? Post back how it runs, thanks

 

[britandy]

Cost was $1800. I installed this kit on the port engine, runs great, running same as the starboard engine, no difference that I can detect.