200 Mercury EFI low power

[sciroccin]

Good evening,



My 2003 Mercury 200 EFI decided it had too much power this weekend and backed off. I was hitting 5600 rpm prior and now i am sluggish and hitting 4500 rpms. I had a #6 coil replaced a few months back when I had a similar problem. I pulled the spark plug wires under load and noted that the #2 and #4 wires did not affect the motors performance at all, however the others would stall the boat. So I guess i am running on 4 cylinders. i went ahead and swapped the #1 (known good)and #2 coil and noted that the same cylinder had the same problem, ruling out that a coil was bad? Tracing further back, would this be a control module problem? Is there something else that would affect/retard #2 and #4? Pressure is 130 on each cylinder.



Regards,



-=Rick

 

[disgruntled merc owner]

Re: 200 Mercury EFI low power

i have a 2002 200 efi with same problems. i cant get on plane i just sit and plow water!!! ive had two different dealers look and try to fix and @ 3500 dollasrs later i still have same problem. now i have it at a mechnic who was highly recomended from a friend and hes had it for a month and still can pinpoint a problem!!! do yo have a smartcraft gauges? hows the fuel pressure? edgar

 

[blazer81.6]

Re: 200 Mercury EFI low power

Ok, a compression check has been completed-good place to start.
Next, you need to check spark on each plug. I would then try to eliminate it being a fuel issue-much cheaper to trouble shoot yourself. Check voltage on cranking battery, if not mistaken it takes 9amps to effeciently operate your E
FI system. A control module could be your problem but some troubleshooting needs to be looked into. I own and EFI and have had similar problems.

 

[sciroccin]

Re: 200 Mercury EFI low power

Edgar, i do not have the smartcraft gauges. Jesus, $3500? What all have they done to the motor? Blazer, I started with the fuel lines, Racor and motor mounted fuel filter thinking possibly an ethanol issue. All looks good, and my primer bulb is holding pressure. Battery voltage appears to be right under 12volts at rest and slightly over 12volts while running. I do not appear to have spark on #2 or #4 plugs. Knowing that #1, #3, #5, and #6 coils were good, i swapped #1 with #2. The result was no spark still in #2 and #1 was firing.

In an effort to expedite the repair of my boat I have sought a local non dealer mechanic who I am hoping to hear from today or tomorrow. I am still open to input on this and will share my experiences as I find out. Blazer, what was the final resolution on your EFI?

 

[disgruntled merc owner]

Re: 200 Mercury EFI low power

well i think the motor has just about been redone comp;etely!!the power head has been rebuilt fuel lift pump rebuilt new reeds new coils new plugs and all other components checked and rechecked!! worse part is this has stumped THREE certified merc mechanics!!! "MERCURY" has been contacted and involved and they are even at a loss for answers!! they sent a test ecm and the motor did the same thing. and if you look at some forums from the past we are not the first that this has happened to but no one has posted an end result! i truly believe merc sent out poorly designed engines and they are not fessing up to it! does anyone know if this is true: for many years merc buuilt a 3.0 200 efi then somehow thought they could rep;icate in a 2.5 ? then decided the 3.0 was better and brought it back??this is what my dealer told me and everyone that ive talked to says that the 3.0 s were great engines? im so confused , disgruntled and at my witts end . this motor has been a nightmare scince sept of 07!! can anyone help??!!

 

[sciroccin]

Re: 200 Mercury EFI low power

Yea, resolution. Turned out to be 2 injectors stuck open and a worn efi pump that was unable to pump enough pressure to the other injectors. A new battery, cable, thorough cleaning of the injectors and used efi pump solved my problems along with a back yard mechanic that was willing to chase a problem down to it's source to solve it. It's like I have a new motor! Thank you to the 2 dealers i have had look at this thing and totally misdiagnose my problems costing me much more money than needed. I finally found a mechanic who is willing to put time and thought into a repair as opposed to throwing parts at it.