runs rough-rich and has a miss at acceleration

[oddysea1]

I have a 2000 350 H.P. fuel injected Merc cruiser-work done so far -plugs-rotor kit -wires -distributor-fuel pump regulator-injectors-fuel filter-still runs rough at idle-smells rich-has a miss during acceleration and higher speeds-looking for other possibilities or reasons . Burns a little blue -mechanic said compression was good.Any scanning devices out there beside the tech mate-little rich for budget. Regards Andy

 

[alldodge]

Motor serial number?

Was it running rich before the injectors were replaced?
What is the fuel pressure reading?

 

[oddysea1]

serial number-ol301745-yes it was running very rich before replacement of injectors-the replacement of the fuel pump regulator also helped-however still runs rough and has a miss accelerating. this is new to me- any advice or guidance on obtaining a reading and what is considered normal would be appreciated-is there a recommended scanner that does not cost 600

 

[alldodge]

Can read codes with a 12V resistor LED and paper clip, on buy one pre-made by Rinda. Attach it to the DLC connector and count the flashes. Only scanner which does supply some info will cost the 600



Being a MEFI-1 ECM the LED is not going to tell you much with current issue. Need to be able to read the MAP and TPS. For the motor to run rich there is either the fuel pressure is high, the MAP (item 16) is not supplying correct info or leaking injectors.

Check fuel pressure at the rail (item 6)
https://www.mercruiserparts.com/bam/subassembly/31608/2716/120

Assuming you didn't buy new injectors (160 each) and hope you didn't buy them from ebay. The ones on ebay are junk. Folks buy them because there so cheap saying they where rebuilt, when in fact, injectors cannot be rebuilt. Injectors can be cleaned and flow tested and if they fail, they need to be replaced.

I would suspect a MAP issue currently.