Converting 350 BB to TBI

"Hey all,

Replacing the 305

"Hey all,

Replacing the 305 in my 1978 OMC 185 with a 87-94 remanufactured marine 350. Am wanting to replace the carburetor with throttle body fuel injection. Found a bunch of stuff online about it, and am pretty secure with the basics. Was hoping you guys could help with some specific stuff.

First, I am using an accumulator supplied by the mechanical fuel pump to get out an air that may get picked up by sloshing. The accumulator will also have a return in the top (I stole this idea from here http://home.hiwaay.net/~davida1/boat.htm) At bottom of the accumulator will go the supply line for the electric pump.

How can I find out if the mechanical pump is going to supply enough fuel for the electric for the 350?

Second: Anybody have any idea where to mount the oxygen sensor? I know many later models have TPI/MPI these days, so it's gotta be doable...just have no idea where.

Thirdly: I'll be grabbing the ECM and wiring harnesses from a junkyard...anyone point me in the right direction for wiring? If not, I'll aks more specific questions when I have the stuff. I imagine I'll have to get a book for whatever truck I grab the stuff from.

wish me luck
Morgan"

Hello Morgan. The mechanical p

Hello Morgan. The mechanical pump will not supply enough pressure to the tbi.I don't know if this website sells after market parts. Napa sells fuel pumps for tbi that don't have to be put in the tank.They are around 70 bucks. jim

"thanks jim. actually, the ge

"thanks jim. actually, the genius of what the guy put together was that a lot of people suggest putting in a sump at the bottom of the tank, or baffles, to keep the fuel from sloshing around at low levels, and air getting into the electric pump. So he built a cylinder that was supplied by the mechanical pump. The air bleeds to the top. The supply to the electric is at the bottom, then the return from the tbi goes back to the cylinder. any overflow goes back to the main tank. was wondering if anyone had a clue as to the rate of fuel provided by the nechanical..."

"You got a BIG problem, Morgan

"You got a BIG problem, Morgan. Maybe you have addressed this already somehow, but:
There is NO compatible coupler for an OMC stringer that will bolt up to the crankshaft of that post 1987 350.
also, what is the BB? in 350BB?"

"also truck EFI on a marine en

"also truck EFI on a marine engine won't work. The torque curve of a marine ignition system is quite different from a truck. You'll be lucky if the boat even gets on plane. not to mention the fire and explosion hazard, broken laws and refusal of insurance companies to cover the vessel."

"by the way, there is no oxy.

"by the way, there is no oxy. sensor on a marine system. back to the drawing board."