MSefi.com read only forum (Jan.15,2018)

I'm starting a new project soon - MSII, V-3 on a Winsor 351 boat motor. I plan on using a GM 454 TBI unit and adapter plate so I can keep the stock manifold. I have a pertronix unit for ignition and everything else is pretty basic. Still not sure if I will go with a WB O2 or not. I feel guilty asking for a tune file, but I won't have much time to spend on the water with this thing....so any advantage would be a great help (even if the file is just for reference, maps, etc - a learning tool). Also, does anyone have advice or knowledge of mounting O2 sensors in boat exhausts/manifolds? Thanks!

I'm doing the same thing on my old Ski Nautique, but fuel & IAC only. I started with the MS-generated tables, and I'm cruising nicely at idle and slightly above. No O2 sensor right now. In fact, unless I come up with a way to use an O2 sensor in the ancient wet manifolds, this is going to be a seat-of-the-pants-tuned open loop system . . .

I'm in the same situation. 454 chevy with 90 lb/h TBI MS-II. Idles great but bogs when I hit the throttle. I have interpolated the VE tables all the way up to 255 at the top right.

My suspicion is fuel supply related. I'm using an E8153 inline fuel pump which shows 10psi on an inline gauge. I'm not sure which fuel pump to use; any suggestions?

I might try the mechanical fuel pump for grins. I at least know it can deliver all the fuel it needs.

Does anyone else have any thoughts?

johnharlow wrote:I'm in the same situation. 454 chevy with 90 lb/h TBI MS-II. Idles great but bogs when I hit the throttle. I have interpolated the VE tables all the way up to 255 at the top right.

My suspicion is fuel supply related. I'm using an E8153 inline fuel pump which shows 10psi on an inline gauge. I'm not sure which fuel pump to use; any suggestions?

I might try the mechanical fuel pump for grins. I at least know it can deliver all the fuel it needs.

Does anyone else have any thoughts?

It sounds like a lack of fuel pressure. Tbi runs good between 12 and 15lbs. Sorry to say but 10psi wont cut it. Your gonna need a good pump that can produce what you need. Im using a ford f-150 88 model transfer pump mounts on the rail and will run it fine. Most likely your mechanical wont have the pressure.

I attached one of my older tunes from before i swapped to a tpi setup. it may not be of much use but you can look it over.

Could you share your MPFI tune? That's what I'm running on my 351.