merc ecu

jj2

Cadet
Joined
Mar 5, 2011
Messages
7
I have a 2001 merc 200 efi it runs great when I first get to the lake the problem starts when I shut it off to fish for 15 or 20 minutes. It restarts fine but when you take off it will only turn around 3000 rpms or it will get up on plane run a short distance maybe 100yds or so and shut off like its not getting any fuel it will restart the first turn of the key and after a few times of this will take off and run great again. I have noticed when it is giveing trouble it idles rough. I have it in the shop and talked to the mechanic a little while ago and he said the #5 and #6 injectors are not fireing. H said it could be the ecu or something as simple as a broke wire he still has som trouble shooting to do. I was just wondering if the ecu could just go bad on 2 injectors or if you know anything else that could be causeing this problem
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,938
Re: merc ecu

Yes its possible on the 01 and up FI. I have only seen 2 of the "555" series ECM/ECU go totally bad.....
 

jj2

Cadet
Joined
Mar 5, 2011
Messages
7
Re: merc ecu

so is it possible to repair just that part of the ecu or will I have to spend $1500 to replace the ecu $800 to rebuild the entire unit
 
Joined
Oct 28, 2010
Messages
923
Re: merc ecu

Before doing that, I would do some more troubleshooting. The injectors get their signal to fire from the primary winding of either #1, #3,#5 and are fired in pairs. I believe this motor has CDM's so that could make it more difficult to diagnose if not familiar with them. But yes a wire could be the culprit.
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,938
Re: merc ecu

The injectors get their signal to fire from the primary winding of either #1, #3,#5 and are fired in pairs.
Only on the EFI's with black box ECU's.
 
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