Mercruiser 350 MAG MPI

[AusFox]

Hi All,
I am in Australia and having some issues with the 350 Mag MPI being hard to start once up at running temp!! I read its a common issue just wondering if anyone can help point me in the right direction considering what I have checked so far and what I hope to check!! I have attached a pic of the ECM for reference, I need to go find the engine serial number!
I have the 4 pin Diag plug, is anyone able to tell me if they have used a pin out process to connect a scan tool to one of these? I am wondering if they communicate VIA a J1708, CAN or K-Line? I have a Launch Scan tool that can communicate with Mercruiser but no plug to suit.
The engine only has approx 100hrs on it, starts first time everytime when cold and runs very well once running but if we shut it down then try re-start it 10 minutes later we need to use the throttle and it takes sometime to fire up and then smells rich.
We have had the injectors service, cleaned the throttle body, cleaned the IAC filter, tried a new IAC Valve, I have removed the IAC hose off the throttle body when it wouldn't start and that made no difference, the temp gauge is showing it running between 160-170.
What's the best testing methods and your recommendations?

 

[alldodge]

Welcome
Part number 865926 is a 555 ECM and it uses a 4 pin connector to link to scanner (Rinda.com)

Being a 2005 it would use Rinda connector 94006 and either Techmate Pro or Diacom

Having to much fuel when starting can be a few things, but I would start with measuring fuel pressure at the rail (item 18). Pressure should be close to 43 psi

Does your motor have the flat style distributor cap?
Do you have one fuel pump under the port side motor mount and a boost pump by the fuel filter or just the one pump?

 

[AusFox]

Welcome
Part number 865926 is a 555 ECM and it uses a 4 pin connector to link to scanner (Rinda.com)

Being a 2005 it would use Rinda connector 94006 and either Techmate Pro or Diacom

Having to much fuel when starting can be a few things, but I would start with measuring fuel pressure at the rail (item 18). Pressure should be close to 43 psi

Does your motor have the flat style distributor cap?
Do you have one fuel pump under the port side motor mount and a boost pump by the fuel filter or just the one pump?

Thanks for this!
I guess I won't be able to use my break out kit for CAN line comms then. Can you put this engine into base timing mode with out the diag tool?
Yes it has the flat top dissy cap.
I will head back to the boat in the coming days to check fuel pressure and the fuel pump set up, I can hear 1 electric pump that primes when the ignition is first switched on.

 

[Scott Danforth]

Change the flat cap and rotor. Those things fail often

 

[alldodge]

Flat top dizzy cap doesn't have a base timing mode. The dizzy is installed as shown

 

[AusFox]

Thanks guys, after speaking with the previous owner he indicated that he purchased this engine as a long motor and transferred all the electronics over from his old MPI to this one.
I am just waiting to get the fuel pressure gauge so I can see what's going on there.
I cant imagine my issue is anything major as the boat starts every time when cold and it runs very well the whole time at all RPM.