Does anyone know if the Merc MEFI 1 controller is password protected? I've heard conflicting information regarding this.

Has anyone used MEFI Burn to tune their MEFI 1 ECM, and if so, what was the best methodology or procedures for working through the tuning process?

If the ECM has never been flashed since the factory it will likely be password protected.

For tuning with MefiBurn, you will need a wide band O2 sensor and make adjustments to the fuel and timing tables.

Call Bob w/ Mefi Burn and he can get you going.

Griswald,

Thanks for the input. The ECM is stock and I'm getting mixed input as to whether the ECM is locked. Bob say's it's not. Others say it is. Looking for a layman in the field to let me hear their experience.

I have talked to Bob and he has always been helpful, but I'm looking for the average Joe's input as to the procedures used in tuning themselves. Things like what table to start on, how they modified it, what was the result etc.

I'm aware of the wide band O2 requirements etc.

This is for a NA application.

Trash, see if you can get ahold of Racer 277 (Sean) from the PB.com boards. He has the MEFIBurn software and tweaked/tuned his 500HP/Whipple setup. He may be able to offer the "laymans" experiences.

I've been working with the software for about a year now and would be glad to share my experience. Articfriends (Smitty) has used it, too.

Guys thanks for the input. I'll be picking your collective brains shortly.

There is a way to lock mefi 1's and 2's although it was never implemented in anything merc did. So, I guess I'm saying, it isn't locked.

RC,

Thanks! That's good to hear.

I used Mefi Burn and Tuner Pro to tune my boat. I'm not an engine guy, but I am a computer geek. I did have to learn a certain amount of engine tuning.
Bob was a huge help and it would have been a very long and expensive process without his input. It took me a full winter and summer to tune my boat properly (massive changes in water and air tem), it was never on a dyno, just a laptop on the lake. My system is a MEFI 3 with a blown 515ci.

Even if you tune with Mefi Burn, you may end up with Keith's DynoJet system. What's not to like about a programmable closed loop FI system? Kieth's and DynoJet's knowledge is proven for decades on motorcycles ( I also run his system on a bike).

The help MefiBob gave to figure out things was indespensible. If you are interested in how the system works and what is changeable (idle speed, shifting, IAC, TPS, etc), the Mefi Burn will show (and can change) that. If you just want to run the correct AFR in all conditions, go with the DynoJet system as well (or only).

R277

Thanks for the input. I'm hoping the process will be a little simpler since I'm dealing with a NA application and only MEFI 1. I like the DynoJet idea, but it has some limitations for me.

I will probably need to tweak the rev limiter and timing so getting into the ECM will be required.