200efi missing

[TiGer85SS]

1997 Mariner 200efi
0G518447

Hello,
I have the above motor and it seems to have a miss in the 3500-4000 rpm range. Kinda feels like it looses power for a moment. I have replaced all fuel lines, fuel filter, rebuilt the pulse pump and the injectors have been cleaned and calibrated by Brucato. I haven't changed the plugs yet but that is one of the things that I'm considering next. Also I don't have the anti-siphon valve in the fuel line. I'm also wondering should I replace that?

Thanks

Tony

[EuropeanAM]

I would definitely try a fresh set of the CORRECT spark plugs before going any further, and then see what occurs.

Anti-siphon valve should be in place, but is not likely to be causing your complaint.

[TiGer85SS]

I would definitely try a fresh set of the CORRECT spark plugs before going any further, and then see what occurs.

Anti-siphon valve should be in place, but is not likely to be causing your complaint.

Thanks Don, I will get those things corrected and report back.

[TiGer85SS]

Just a update kinda of. I changed the plugs but I haven't had a chance to run it. Hopefully this coming week will be better for me.

[TiGer85SS]

Well, I went out yesterday and the missing between 3500-4000 is gone however, when I am coming out of the hole it seems to be loading up sometimes this problem was there initially as well. The only thing that has not been cleaned in the fuel system is the VST. This is going to be my next step. I have also heard of people having similar issues needing a ECM so I might have to find someone I can borrow one from to test that out as well.

[EuropeanAM]

Before you tear into the VST, check the FUEL pressure, and record results for:

-Idle
-Under Acceleration
-15/30/60 seconds after engine shutdown

[TiGer85SS]

Before you tear into the VST, check the FUEL pressure, and record results for:

-Idle
-Under Acceleration
-15/30/60 seconds after engine shutdown

Would I need to do this on the lake or could I check it on the house at the house?

Will do

[TiGer85SS]

I got a chance to go to the lake today after I changed out the battery for one that Don had recommended and the engine ran great. However, I think that the old battery may have messed up my voltage regulators because I'm getting around 16 volts while running so I think the main problem may have been the battery all along. By the way I bought a 27 series interstate starting battery if anyone wanted to know.

[EuropeanAM]

Fuel pressures can be checked on a flush attachment (pin-style Mercury or Quicksilver earmuffs).

Verify that voltage AT the battery with a DVOM. Should NEVER exceed 14.6 VDC.

Inspect voltage regulators and bullet connectors for burnt spots or browned/blackened/burnt connectors. If these are noted- you'll need to replace BOTH regulators, and any damaged connectors.

Replace regulators IN PAIRS, using only OEM Mercury Components (important) if voltage is exceeding 14.6 VDC.

Also note: Make sure that connections at the battery are correct- Engine cable FIRST, remaining lugs Largest to Smallest, and finish off connection with a stainless locknut (do NOT use wing-nuts).

[TiGer85SS]

Thanks Don, I will be replacing the both of the voltage regulators. Im just amazed about the battery situation. I will never have a deep cycle battery for my motor again.

[TiGer85SS]

Replaced the voltage regulators with the new style. Volts are stabile and motor seems to be running well.

[EuropeanAM]

Make sure you're using a WET cell CRANKING battery, and that battery cables are installed:

-Engine cables FIRST
-Remaining lugs Largest to Smallest
-Finish off connections with a Stainless Locknut (do NOT use wing-nuts).

[TiGer85SS]

Make sure you're using a WET cell CRANKING battery, and that battery cables are installed:

-Engine cables FIRST
-Remaining lugs Largest to Smallest
-Finish off connections with a Stainless Locknut (do NOT use wing-nuts).

Yes Sir that's the way I did it.