hard starting Merc 150efi

[BestMate]

So the engine (2001) has decided to not run this summer. Actually the problem started earlier this year in February.

Hit the key, engine just simply turns over, never really fires up.(vid taken last Saturday)

https://www.youtube.com/watch?v=xRbMjQwUVV8

So today I go back to the boat to get something t odayand decided to try and start it. same simple just turn over but eventually goes.

https://www.youtube.com/watch?v=9vGpgs-OuTU

when it eventually runs and after giving it some throttle burst, engine still idles rough.

https://www.youtube.com/watch?v=XpukO5B2CjM

ideas? Fuel pump, Stator coil, ECU? Fuel is good, only 3 weeks old and problem was happening prior to this fuel load. New hose from tak to racor->racor to engine and new filter in April.

When I had the yearly service the engine NEVER did this for the mechanic - started perfect first kick every time.

 

[pdecat]

Start by checking if fuel spurts out of the Schrader valve on the pressure rail then check for spark.

 

[BestMate]

Bruce - check for fuel at the pressure rail when the the key is on or when cranking/running?

 

[pdecat]

I think it usually stays pressurized but with key on you may hear the pump if the pressure is low.

 

[Sandy]

And , of course , if there is a lanyard kill switch, confirm the "key" is attached properly. ( -not the culprit if it starts eventually).
If you suspect flooding , advance throttle to full WOT until if fires, to shut off injector pulses.
You might try disconnecting the engine/dash harness then jumping from the battery to solenoid and engine block ground or even attempting manual start if that engine is equipped for that. Just remember ignition module engines require a certain minimum ignition voltage (~~~10VDVC?) while cranking to wake up.

Did you check the plugs to see if they were getting loaded up?