Fuel Pressure for 2003 6.2L MPI?

[ColoSR]

Hi All! My 6.2L MX MPI (S/N 0M600244) with bravo 3 had been losing top end power last summer so that it wouldn't get over 3,600 rpm by the end of the year. It also would go through periods when it wouldn't get over 2K, but eventually that would work itself out. It got new 22P props, spark plugs, wires, and distributor the summer before last and ran fine at WOT. New fuel filters prior to the season. The engine isn't throwing any codes on my vessel view mobile.

I sent it to the shop for them to take a look, and the tech told me that it isn't showing any codes and he couldn't find anything wrong with it. I asked him about fuel pressure and he said it was on spec at 29 lb. Does this sound right? I was thinking that it was supposed to be up at 42-43 lb. If the fuel pressure is right, are there things that I should ask about?

 

[scoflaw]

Research what it's suppose to be, I'm with you at 4 bar.

 

[Shenanigans77]

Hi All! My 6.2L MX MPI (S/N 0M600244) with bravo 3 had been losing top end power last summer so that it wouldn't get over 3,600 rpm by the end of the year. It also would go through periods when it wouldn't get over 2K, but eventually that would work itself out. It got new 22P props, spark plugs, wires, and distributor the summer before last and ran fine at WOT. New fuel filters prior to the season. The engine isn't throwing any codes on my vessel view mobile.

I sent it to the shop for them to take a look, and the tech told me that it isn't showing any codes and he couldn't find anything wrong with it. I asked him about fuel pressure and he said it was on spec at 29 lb. Does this sound right? I was thinking that it was supposed to be up at 42-43 lb. If the fuel pressure is right, are there things that I should ask about?

I have the same power package. 42lbs of fuel pressure at the rail is what you need

 

[ColoSR]

Thanks all, it sounds like 42-43 is the right range. Apparently Mercruiser misprinted some of the early #31 manuals with 30 psi instead of 43 psi.

 

[rob954]

Thanks all, it sounds like 42-43 is the right range. Apparently Mercruiser misprinted some of the early #31 manuals with 30 psi instead of 43 psi.

Did u get the low fuel pressure sorted?

 

[ColoSR]

Yes, it is supposed to be up around 42 psi. My main pump was failing, but the helper pump was delivering 30+ psi masking the issue unless the engine was under load. They had to put it on the dyno to figure it out.

only problem now is that the access is so bad they have to unbolt the engine from the mounts so that they can swing it to create clearance. Never ceases to amaze me how accurate the Break Out Another Thousand acronym is

 

[ColoSR]

Turn out that 42 psi makes the engine run way better. I didn’t know she would run this fast.

I used to run on par with my buddy with a carbed 350 and bravo 1, I blew him out of the water yesterday.