The cost of an HP ecm and complete wiring harness with everything you would need to run the majority of Merc's EFI big blocks, or a Whipple SC, from Summit racing is $1449. All the sensor connectors plug right in. There's about 5 wires you have to hook up to get it running. It takes about 2-4 hours. You can make it as simple or as complicated as you like. There are a few options for ignition systems and you can have the computer control the timing, or let it run on it's own. Rather then listing all the possible applications and conversions options, if someone has a specific install question I'd be happy to try and answer it. There is no secret voodoo here.. As a comparison, how much does it cost to have a "tuner" drive around all day, or two days, in your boat to tune an obsolete operating system that is now only optimally tuned for the conditions and boat set up on that specific day? Ask anybody who has used MEFI burn to tune their own how many hours they've got into it, and how much of a change they've seen even just from running different props. Ask anybody with a MEFI 3 how it works past 6300rpm.. There's probably only two guys in the US, Dustin Whipple and Mark Boos, who have the knowledge and experience to really do a complete tune for a marine engine taking all possible conditions into account. I'm not selling this product or saying it's for everyone out there. I'm simply passing along my experience in an effort to help anyone who is interested.

On the commander I don't believe there's a provision to do a "free air calibration" so all you can do is compare it against a new sensor. It's never a bad idea to keep a spare anyway. :drink:

Haxbyspeed
Does the Holley system have idle control methods besides IAC to help hold the idle. My concern is with blown engines on heavy boats with big wheels they usually have difficulty holding idle when shifting in/out of gear during docking.

Any insight for us in this area?
Rick

I have heard of guys running 2 iacs in crazy applications on one motor, I have seen the "extended" range IAC table on the mefi's but have never heard of a actual extended range iac motor. On my own blower motor I couldn't get enough air thru at idle warmed up even to keep motor idling without having IAC open so far that it could still open more to recover (IAC counts were maxed out at or past 160) so I ended up drilling a couple 1/8" holes thru the throttle blades, I started out small and kept making holes bigger and bigger until IAC was between 25-50 counts warm, Smitty

With the aftermarket stuff, you would normanally unplug the IAC, open the throttle plates enough to keep the idle 50 rpm under your target then plug it back in. From there you can set the Iac speed and distance. And you have a spark offset table to help smooth things out.

Do you have part #s for the ECU and wiring harness that would work to replace a N/A MEFI 3 system? I don't find them in my Summit catalog.

Why didn't you give it more throttle blade?

Yes, I like to drop the base timing at idle to around 10-12ish, or sometimes lower, and open the throttle blades to maintain the rpm. I also don't get too hung up on AFR numbers at idle and just give it what it wants to idle solid without hunting. As soon as the engine goes into gear I'll ramp the timing up to the high 20's low 30's and add fuel as necessary. With a laptop or the touch screen hooked up you can see exactly what cell your ecm is reading while putting it in and out of gear, then adjust the fuel and spark in those cells until it will barely change rpm between shifts. Once you get it close the computer will continue to fine tune it too.

I'll get the numbers for ya. Get rid of that other junk and never look back. I'll send you a base tune too that'll be really close.

Thanks, i have an Edelbrock headed 540 with the ported intake that i got from you. Looking for around 600hp