96 Mercury 175 EFI random power loss

[Dman364V]

Hello guys. I have a 1996 175efi that is giving me a fit. I have spent over $2500 on this engine(unexpectedly)since I bought the boat last February on various other issues and it's still not right. It has no trouble starting and runs fine most of the time. It will randomly lose power and run rough. During this period you can push the throttle wide open and it changes nothing. If running on plane it will set the boat down when it acts up. It may be a 2 second jerk or it may last 3 min then it will take off like it never happened. It does it in all ranges from idle to full throttle. I may go fish 6 hours with no issue then fight it the whole time next trip. It's so sporadic I have no clue what to look at. Also only turns about 5300 rpm wide open. Any input would be appreciated. Thanks

[BassCat'99]

have you checked it for a fuel filter? Inspect fuel lines and bulb. Could be the boxes or another multitude of things. Post your motor vin so the motor would be properly identified.

[Dman364V]

The fuel filter and water separator have both been replaced . Serial # OG321121

[BassCat'99]

Doe's it just quit or is there a slow down before shut down? Also could be electrical. Hard to say with out testing.

[Dman364V]

It never dies, just instantly cuts back to a rough idle then resumes like it never happened.

[BassCat'99]

I'm thinking electrical. Believe your going to need someone there to trouble shoot the system.

[WisconsinF]

Back to the fuel thing....have your replaced ALL THE LINES? You wouldn't believe what some of us have found!!

[Dman364V]

I will look back through them again but I think I got them all. I think lol. Thanks for the replies

[JOE54]

Dman you likely have a electrical issue with a switch box or loose driver in ecu when it does it bump on front of ecu = stops miss bad driver ,and check for spark on all cyls when miss occurs

[Zx175Bassman]

Must Check ECU for intermittent problems

[Dman364V]

I will definitely try that next time I'm out! I really appreciate the help and will post back as soon as I can get back out

[Batman1977]

+1 on the ECU.

[Basser100]

Can you still get new ecu for a 95 200 horse mercury EFI?

[EuropeanAM]

Probably not- but they can be repaired.

[Bruce2]

Can you still get new ecu for a 95 200 horse mercury EFI?

Sounds like your ECU is dropping injectors, that's what was wrong with mine...you can get that ECU repaired...brucato, cdi and simonsmotorsports rebuilds them also..http://simonmotorsports.com/ I think I saw simons say 695 to repair one, not sure.

[JOE54]

Can you still get new ecu for a 95 200 horse mercury EFI?

no not avail from merc anymore