MAG 350 MPI (2002) On going issue help please.

purplehayes

Member
Apr 17, 2010
76
Nanaimo, B.C., Vancouver Island, Canada (West Coas
Boat Info
290 Amberjack 2002, Lowrance HDS7 and HDS8 networked with BR24 and Standard Horizon GX2150
Engines
Twin 350 IB Merccruiser
Hey Folks,

I have thrown a few parts at the problem and have had a tech working on it but he is so busy that he basically doesnt have time to troubleshoot the engine.

Port engine, shaft drive. Basically the issue started with trouble starting when hot and a strong exhaust smell to the same but a very strong smell and loosing power.

It wont give me power to get on the step and lags at open throttle. Basically it bogs down when I put the power on to get up...but catches up with the Starboard engine once it is up.

I have done:
Caps, Rotors, Fuel Filters, TMAP sensor, PCV Valve, IAC Valve

Tech has:
Tested the fuel pressure in the system and it is good.

I feel that maybe I have lost power to a cylinder either with a plug issue or a power lead issue. Plugs and Leads are scheduled for tomorrow.

Any comments or ideas would be great.

Thanks
 
Do a compression test as a starter... a leak down if needed.

Fuel pressure "good"... how was it tested? Only at idle, or while under power?
 
Wires and plugs should do it.
 
Check timing and compression while the plugs are out. And take a hard look at plugs as they are pulled. The heavy exhaust smell may be associated with excessive blow by.
 
Smell of exhaust? Do you mean a rich or raw fuel smell?
Can your tech check live data?
Possibly faulty injectors or even a bad coolant temp sender causing over fueling?
 
Opps. My bad! Check the timing b4 the plugs are pulled. And, while the ER and plugs may be warm or hot after engine run it is recommended that the compression be checked while the engine is warm.
 
Last edited:
I had something like the problem you had. 1998 290 sundancer with twin 5.0 efi. Problem was a week fuel pump on 1 motor
 
Sounds like bad fuel pump. But get a tech with Rhindas if your motor has smart craft and they can run a series of tests to rule out fuel pump, injectors and or bad sensors. If its getting the fuel but not the spark usually would be indication of bad cap but you said you did that. Go after fuel and timing which could be bad sensor as timing is not adjustable and set by computer.
 

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