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2006 Mercury 4 stroke 90 EFI fuel problems ???

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fordrocks

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I am having a problem with my 2006 90 Mercury 4 stroke efi. It starts, idols and runs great but at full throttle it keeps wanting to shut down every now and then. feels like it's out of gas but if i drop to half throttle it runs fine.I can troll all day with no problems and it doesn't happen every time i use it. I have changed the plugs, fuel filter, oil, checked the pick up tube screen in the gas tank, added water remover and fuel injector cleaner to the tank and sprayed a can of fuel injector cleaner into the throttle body while running. i'm still having the same problem at full throttle, every now and then it feels like the fuel is shut off. but runs normal when i back it to half throttle. Could this be a sensor issue? anyone had the same problem with this engine?
 
The fuel pressure regulator is inside the FSM, and you will have to remove the intake assembly to service the FSM. Another possibility which would cause your problem would be a faulty IAC. I think the best way to diagnose this is to first eliminate the possibility of an IAC (or other sensor) failure by having the outboard scanned at a dealer service location. I would also suggest that if you are going to "DIY", you get a hold of a factory manual for your model.
 
I'll bet it is one of your ignition coils. I had one go bad twice on my 2006 60Hp, and it did exactly what your explaining. Three years ago the dealer replaced one under warranty. This year it was doing the exact same thing. Went back to the dealer and was told that they have had a lot of these problems. Dealer said Mercury had a (unpublished) recall on these coils. The dealer replaced all four, even tho they were out of warranty now.
 
have you ever run old e10 gas through it?..i had the same problem years ago on a 60 merc efi...ran perfect at 2500 rpm.. it was a new motor so i let the dealer clean it out....cost me 350 but that included 2 new 6 gallon tanks plus a better water filter..
 
Please explain why it won't- then I'll explain why it will.
Click to expand...
The IAC is controlled by the ECU and its basically a bypass. It lets a controlled amount of air past the closed throttle plate to regulate the idle and once throttle is open it basically does nothing. Since the engine idles,starts,trolls accelerates its not the IAC..You state it runs at 1/2 throttle but not WOT I would suspect the fuel pressure is beow spec as it needs more fuel as injector pulse is longer at WOT than 1/2 throttle and 10-15 psi pressuse difference can cause issues.
 
Last edited:
Looking for solution to fuel flowing through Air Vent Assembly and out overflow drain tube through the top of it. New High pressure fuel pump and filter installed last month
 

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What was the final resolution to the problem?
fordrocks said:
I am having a problem with my 2006 90 Mercury 4 stroke efi. It starts, idols and runs great but at full throttle it keeps wanting to shut down every now and then. feels like it's out of gas but if i drop to half throttle it runs fine.I can troll all day with no problems and it doesn't happen every time i use it. I have changed the plugs, fuel filter, oil, checked the pick up tube screen in the gas tank, added water remover and fuel injector cleaner to the tank and sprayed a can of fuel injector cleaner into the throttle body while running. i'm still having the same problem at full throttle, every now and then it feels like the fuel is shut off. but runs normal when i back it to half throttle. Could this be a sensor issue? anyone had the same problem with this engine?
Click to expand...
 
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