Trouble on 502 mpi engine , help wanted !
 

Hi , This moring I was sailing out of the harbor , arriving at sea I reved the engines and after cruising at 40 mp/h , abouth 1 or 2 minutes later , the starboard engine lost its power . When in neutral it would reve to 4.500 rpm , but I could hear that not all cilinders were workong , it sounded like a 4 cilinder.
Then i tried runninn a few minutes at 2.500 RPM on the other engine en opening the trottle a little more in the starboard engine , hoping it was only some dirty sparkplugs ?? but after 10 min. i gave up, it wouldend reven over 1200 rpm when in forward. So i checked the ecu for any DTC's (I have a small one with flashing led) and it showed code "12" so this means , no codes in ecu.


Oil pressure at 1200 rpm was 40psi , oil temp = OK , engine temp = OK too.

So far I have changed th espark-plugs , new cables , new rotor , new distributor cap , new ignition module in distrubutor , new fuel filter .......
So please help.............................

Carbs or FI?

Title of post says MPI so I'm guessing.....injected :party-smiley-004:

:o:o

You need to check fuel pressure at the small port on the fuel rail that looks like a tire valve.

sounds like a fuel problem.