You sure that's a MEFI 3, not finding a TBI with a 3, can find a 1

Is it TBI or MPI and which Dizzy, EST maybe?

It is definitely TBI, and when I plug in the techmate scanner it says "MEFI 3 computer found"
Im pretty sure its not the EST, and it is the thunderbolt style distributor

Est dist

https://cimg3.ibsrv.net/gimg/www.off...a345e2896.jpeg


tbolt dist


https://cimg8.ibsrv.net/gimg/www.off...5028d5a6d6.jpg

From 99-2000 the MEFI 3 came out with TB5 Dizzy
Sterndrive is 8* and Inboard is 10*

Put a advance timing light on it and see it your getting full advance

What Octane fuel are you using?

Using a Techmate you may not see that a code 44 shows up. If it is showing up then it will retard the timing

It is definitely the thunderbolt

I just have an old school timing light, are you thinking maybe the techmate is reading inaccurately? Thinking back on it when I had the techmate hooked up I was only seeing 6-7 degrees at idle. Another thing to note is that my tachometer has been reading inaccurately, I can switch it from between 4-6-8 cylinder, and it was better for a little while, but now its back to being inaccurate. The techmate reads accurate RPM all the time.

It did have about 30-40 gallons of fuel that sat in it for a little over a year while the engine was getting rebuilt, but since then another 30-40 gallons of marina rec fuel has been added

Couple other things that I should mention:

-Last time on the water I remember feeling that the starboard riser was hot to touch where the port one was cool. Thinking back on that now I remember pulling an exhaust shutter out of the exhaust passage in the transom assembly when putting the outdrive back on. Im wondering if the other exhaust shutter is lodged somewhere in there and blocking flow in the starboard side.

-While the engine was getting rebuilt I also replaced the lower on the bravo 3. Im 99% sure I confirmed it was the same ratio as the old one but I have made mistakes before...

-I still have yet to get an actual fuel pressure reading because I can not come up with the correct fitting. Techmate said around 12 gph under full throttle

Can you drill thru, then tap for say 1/8” npt fuel psi gauge , the plug in the ‘return’ side of tbi ?

#3 here:
https://www.mercruiserparts.com/bam/...31629/2340/130

(some places list in stock, if you eish to try it on a spare part)


https://cimg9.ibsrv.net/gimg/www.off...e5f9bf8bbb.gif

The Techmate will read accurate, disregard the timing light
Lets get more into the ratio

You can remove the fuel pressure sensor and install gauge there
The low oil and fuel pressure may be an indication that the 5V reference voltage may be low. It can be low by one of the sensors drawing to much current. What does the Techmate show the voltage is?

You didn't happen to replace the injectors?

For the ratio:
The old lower was corroded beyond repair. I got a used lower off ebay and would have spun the input shaft 1 turn and then counted how many times the propshaft rotated and make sure both old lower and new lower are the same.

I will try and locate the fuel pressure sensor today and see if my gage fits.

The low oil and fuel pressure warnings have not been present the last 2 times I have hooked up the scanner. All im getting right now is "general warning #1" I will hook the scanner back up to see what voltage I am getting.

I did not replace the injectors. I did take a very short video with the hatch up, and air cleaner off to watch the injectors under load. The port injector seemed to be flowing a little less, but hard to say from a phone camera.