350 MAG MPI fuel code error

Black_Diamond

In the process of making my dash digital, I has a sea trial done to make sure all worked.  In the process, found out a fault code for the fuel from the starboard engine is popping up and limiting engine power to ~90%.  This has always been the engine that under load would drop rpm or no throttle response at higher throttle position when under load (5+ people on board / full fuel / water loads)  A lot of the problem for sure was being over propped, that one solved. 

This is a 2003 model, Cool Fuel II, only the single fuel pump version.  Filters are all good, fuel is good.

Any thoughts to hunt this down?  Was not a fuel pressure fault.  Something on the electronics side.

Michael T

Is there a fuel pressure sensor? I had trouble with water pressure sensors - even when they were replaced "ghost" code still erratically emerged limiting rpm....until the area Mercruiser representative  deleted the code via his computer program. I realize that you may not have a VV programming issue.....could you have a faulty sensor?

Black_Diamond

Here is what I am told:

The error message was on the starboard side under acceleration and was "fuel pump ckt".

no beeps. 

FWIW:  The orange wires to the alternators are disconnected too. This was a Merc Service Bulletin from once upon a time b

212rowboat

anything new with this? 

something to consider... much of these EFI systems rely on ohms/impedance for built in tests.  an exposed spade on an EV1 or EV6 harness connection (on the injectors) can cause all kinds of grief- especially on boats exposed to hostile environments. 

as an example i chased a misfiring cylinder on a mopar 360/408 for literally weeks.  it turns out the spade on the offending cylinder's EV6 connector was 'oh but slightly' twisted from some jackalope (me) pushing it on too hard.. it slid into the connect just fine, but the spade didn't sit flatly in contact with it's seat... which caused strange impedance issues but not all the time.  also, a spark plug wire running over a harness can also cause some strange issues/readings- meaning there is nothing wrong but the 'reading', which the PCM reacts to as if something was/is wrong, if you can follow that. 

Black_Diamond

Nothing too new.  Out of the water till spring so hard to chase. 

In an Old discussion from Al, I am going to reconnect the orange wire at the alternator/starter. The wire was cut at Rinker at install, something about the charge circuit and the battery isolator. Anyways, this limits the voltage to the ECM and the fuel pump apparently to ~12v rather than the alternator output. Thus can impair the fuel pump at higher load demand points.  

Your point on connections is well taken. I was planning on just going thru them all over the winter.