I want to upgade my 4.3 l omc marine engine from a carborator to throttle body fuel injection. I have available a 94 s10 blazer doner car with a vortec fuel injected engine. Can I install the vortec intake and associated parts on the mairne engine?
It can be done but it is very time consuming.
I use an 87 Astro van intake sensors and computer on my 86 OMC.
After six years I am still playing with it.
Runs good and easy on gas.
Got lots of info from DIY-EFI.
You HAVE to change programing in the computer.
I am running a closed loop system with one oxygen sensor in the starboard manifold.
Your 94 computer is not as good for a boat because it also controls the transmission.
Just to give you an idea what your in for.
Im in the middle of my project with putting an 95 astro 4.3 engine in my boat.
I had my ECM in for tuning at a really good company here in sweden.
The converted the ECM from automatic > manual
They removed oxygen sensor, EGR controll, VSS signal.
But he said that it would be nice if i can run it in closed loop because
in the original program there is a feature called highwaymode.
If you have same throttel position for a little longer it goes into HW mode and uses O" sensor to lean out the mixture. So he gave me a pretty nice tip and that was to use the EGR port and put a pipe from that port to the exhaust pipe where it turns down in to the sterndrive.
That flow is enough to messure O2. And since this is a cpi injected engine all cylinders will get the same amount of fuel and i only need one 02 messuring point.
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We build "street engines for marine use all the time. If it is fresh water cooled there are not that many differences in the engne itself. On engines that are frome the manufacturer with raw water cooling they used ceramic in the water passages to slow the inevitable rusting to come as well as ss valves, hardened exhaust seats, bronze guides in the heads, stainless steel head gaskets as well as brass freeze plugs and a cam to push the torque to more marine usage. I have seen people take and swap in used motors with low miles, put in an "RV" cam, some brass freeze plugs and the thing ran well for years.
That being said, it is correct to say that coast guard regs are quite specific on how fuel is pumped/what can/cant be used in a fuel system on a boat. Marine fuel injection typically runs on open loop and the pump is mounted on the engine with a low pressure cut off switch.. so if there is a leak it will kill the motor.
I am working on making a custom fuel injection system for my boat and if anyone has any ideas/questions/comments, feel free to contact me. I will probably be using the megasquirt or microsquirt system and build a custom manifold since I dont have much space.
Hope this helps
Bdd
1988 275 albemarle
twin custom 425hp sbc engines
lovin life at 40kts
The only issue here is it would not be legal. Fuel items are built specifically to marine standards including injector-orings and anything you can imagine due to the risk of fuel leaks in a boat bilge(a dangerous combo I'm sure you can imagine). The other issue is that boat motors even though they look just like the street version have a totally different power curve achieved with different cams and other design changes. Street fuel injection probably wont work with it. Ive seen many street motor swap ins and the customers were really disapointed with the power loss afterwards. Marine carbs are very high flow and jetted large. Who takes fuel mileage on a boat? If you did youd find it to be attrocious! Anyway Crusaders marine corp makes injection and manifold setups for gm engines but hoestly I'm not sure if they ever did for the 4.3 Hope I helped. Thanks
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If its a good doner engine it would be easer to chg.out the whole engine. If not i think you have to chg.heads too, to match the intake. You will also will have to have the computer and the wireing and sensors from the doner, that way everything will work right.
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