If you have a nice consistent fuel curve already and it it's a little lean or rich, you can use the fuel pressure adjustment to fix the condition.

The a/f meter will tell you if there are "spots" that are different etc.

You would really only need to program if you find a range or speed that for no apparent reason becomes much leaner or richer when running the boat.

Better to put the bung in the forward most part of the riser or elbow. You'll need a pretty talented welder to install in so it won't leak, etc.

Thanks for that, on the dyno my numbers were a little lean but I was told the numbers would come down with the engine in the boat with the wet exhaust. My numbers on the dyno were 13.56 @ 3000rpm and dropped to 11.56 @ 4700rpm so hopefully if I am still a little lean when I use the A/F scan tool I can adjust the fuel regulator......:confused:

I also agree about a "good" welder.....:coolcowboy:

Again, you need to check the af's while running the boat in the water on plane. Adjust the fuel curve according to the engine builder's recommendation (not what someone on a forum tells you).

Matter of fact, I'd have them make sure your tuning is acceptable by their standards.

No reason for you to be responsible for fuel trim if you're buying/building a new engine.

Kind of a different situation here.....I had the engine "built" by a very good local shop but they build stock and sprint car motors and very few marine MPI motors that have a Procharger.....they did an awesome job on the build but we needed advice from various sources, see attached thread.

http://www.offshoreonly.com/forums/g...she-lives.html

Long story short, I have ordered the A/F ratio scan tool and will run the boat with that and the lap top and see what umbers I get and go from there....as soon as it stops snowing..!!!:traurig001:

Wideband 02 with data logger and RPM works the best. You can't fix rich and lean spots with the regulator, it makes changes across the board.

This is what I ordered, I can change settings without sending the ECM out???

http://www.innovatemotorsports.com/products/lm2.php

I may be wrong but, I believe that's a data logger, you would need tuning software and a laptop to make changes to the ECU.

The Innovate LM2will only monitor the A/F. If you have MPI/EFI you can somewhat adjust the mixture if it is close to what it should be, but as hallj stated you can't change the shape or curve of the mixture.
Jeffswav has the Holley EFI setup so he can change the setup using his laptop, but with the stock MEFI1,2,3,4 you would better off to pay someone to reprogram it for you and several builders on the forum can do that for you.

There is no way to change fuel curve in the box without someone flashing it.

The link you put up is for the tool to "measure" what's going on.

You can use the fuel pressure regulator to change it up or down as long as there are no trouble areas. The meter will tell you if there are.

Otherwise, if you have spots in the rpm range that are rich or too lean in the curve you will have to reprogram it.

You really ought to have this done for you by a professional based on what you're saying. If you built a nice engine with someone and they are leaving it up to you to finish it... I don't know... And you are playing with one aspect that will kill your motor if you are not sure of what you're doing.

Having "car guys" build boat engines never seems to smell right.

Just be careful and don't lean it out for very long.

If the reprogram is necessary and if you send it out, you'll need to keep testing until you know what you have.

I hear what you are saying, problem is, there are no marine engine builders around here......closest I would trust is Alex Haxby who is in Vancouver and it is major time and money to get the boat over there. I am happy with the build and happy where things stand right now but when the weather permits and I can get some water test time under my belt it will be nice to monitor the engine and make sure we got it right, if not, we can make changes based on the info we get.

I had my ECM re-flashed by Mark Boos but perhaps I did not supply him with all the info he needed, on the dyno it seemed to run a little lean, but until we run it on the water under load I don't know if we got it right.

The A/F reader I ordered comes with software and a laptop connection so I assume certain things can be changed.......as far as getting a "professional" up here to set it up for me, it ain't gonna happen unless I fly somebody in......the other half would shoot me.....:eek:


Thanks for all the feedback boys......:coolcowboy: