BUP

iTrader: (9)

Holley had a TBI set up in the early 90's then Hirel came along in which the next year changed to Cutler - that efi system had a side mount ecu that was self learning. In 1996 or 1998 Holley bought that Hirel / Cutler system and have improved upon and continue today. I have installed the hirel / cutler way back in those years. Still have the manuals and the diagnostic manuals for them to.

BUP

iTrader: (9)

If you really know how to tune like these auto tuner guys with the new systems out (ECM's / ECU's) on the market currently and whats coming down the road - this is the way to go with these aftermarket units. The current marine ECM's and Mefi 6 along with these other systems ecm's on the market are way behind compared to whats really out there. And I mean years behind.

Also Australia is another leading manufacturer in fuel injection ECM's / ECU's.

GPM

I have one of each sitting in a box in the basement. I believe they called the TBI unit ProJection.

airjunky

iTrader: (2)

Oh the joy . The cutler hirel had that nice dart style high rise intake billet rails and progressive linkage throttle body i swear mine had accell ecms you could load a base program from a floppy
they come up cheap on ebay with what would certainly be a zorked ecm.lots of reasonable ecm options including merc mefis converted gm ecms the street rod guys use i use a fmu to help dial if needed .plan on putting one on one of my jet boats for a little bling factor maybe use a bit less gas .to me the asm style units still look cooler though especially in blue

airjunky

iTrader: (2)

Think the holley version of that now is the commander 950

BUP

iTrader: (9)

I hear you and this always cracks me up in the OEM marine schools because they will preach about how you can not use any other EFI / MPI systems including aftermarket systems along with ecm's / ecu's because you can not get that precise tune for the marine environment plus they will fail from heat, vibration and corrosion issues in a very short order. A lot of marine techs believe that as well.

I always want to break out my pics or the Megasquirt MS3 pro controller operating and its parameters monitored while water being sprayed on it for 3 straight days. Amazing they really think this way still.

Sterling and a certain big name race team use aftermarket ECM's for their fuel injected engines that really are not even marketed for the marine side. Just saying

kidturbo

BUP, your probably someone who can answer this question. Wasn't the original Merc MEFI actually just the Accel DFI system from the early 90's? I purchased one of the first DFI units from Accel in like 92/93 for our street race car. It was the bomb back then, and sure beat burning ROM chips... Then recall seeing that same tuner serial connector on early MEFI systems around 2000 something. But with the ECU in different waterproof case and Merc stamped on it. Always wanted to jack into one with my DFI software and see..

As for tpabayflyer, if your considering going EFI, you'd be way ahead to wait and do it right when your ready to make the change. As listed above there is plenty of good options out there now, and all are port injected. TBI is so 80's anyways.. You can even build your own setup easier then most people think. Good intake, injectors, pump, and fuel rails, then pick your ignition system style and top it all off with a programmable ECM/ECU. Also with modern software like EFIlive or HP Tuners, you can even use automotive ECM's and make a monster cam blower motor purr like a kitten in a boat.

I owned the first Duramax marine conversion boat and hated it, before I tuned it with EFIlive. After some extensive tinkering, that torque monster shifts smooth, idles low, has amazing fuel economy, and then hang the __ on when you drop the hammer. That's what a properly tuned port injection system should give you over the best matched Holley carb setup.

airjunky

iTrader: (2)

Gm pioneered the reflashable ecm . Before obd2 before merc sold the first mpi motor but after they were all in bed with the lt5 . And yes those were the good old days. And the c4 ecms from that era were out in the elements in a ugly marine kind of way .basically a overgrown 502 mag ecm that supports closed loop bcm ins and outs ect .put mine on russ collins injectors that support twice the hp of stock all good so far

airjunky

iTrader: (2)

They had that old small block ram jet set up i dont have a clue what they ran it on have lived 20 hard lives since yhat day lol . Think that was late '80s damn brain cells

Quick2500

They were always "flashable", GM just moved to bring it out of the geek lab and into the shop. All he latest and greatest tools do is present a GUI to alter the source code and a compiler to go with the ISP.

**edit in: Yes, I'm a geek**