2000 Mercury 200EFI intermittent loss of power, SN 0T158142

I am trying to troubleshoot a low hour (around 400h), year 2000 Mercury 200 EFI, SN 0T158142. Compression is good (all between 115 and 120 psi). Fuel components are good (new fuel line, new in-line racor, new fuel filter, clean fuel pump screen, good fuel pressure, etc.) The only major component that has not been cleaned/serviced are the injectors. When the motor runs, it runs great. Starts quickly, idles well, jumps on plane, and reaches rated RPM (around 6K when lightly loaded).

A little back ground:
Last year, on my way to the Bahamas, I stopped to take a break and eat a snack. Prior to this I was cruising at about 4500rpm for about 2 hours. Pulled back the throttle, and let it idle forward while I ate a sandwich and had a drink. When I tried to throttle up, the motor would not get past about 1500 RPM and was shaking badly. I shut it off, restarted and tried again with same results. The motor would start, but idled poorly and would not throttle up. I tried pumping the fuel bulb and that made no difference. I changed the Racor filter/separator and the internal fuel filter - and that made no difference. Since the motor was still running and I was still in the middle of the ocean, I put it in gear and idled the rest of the way to Bimini Bahamas.
The only other issue that could be related, is that I had an low oil alarm during this voyage. The oil tank on top of the motor was not filling as fast as the oil was being consumed, but it was at worst low enough to trigger the alarm when I hit a wave just right. That issue was later diagnosed and fixed - it was a cracked oil cap. As a precaution, I am about to pull the oil injection entirely and go to pre-mix.

When I arrived in Bimini, one of the locals saw me trying to fix the motor and came to help. Unfortunately, we were not very systematic in our attempts and messed with everything. We unplugged a bunch of stuff, messed with timing, messed with idle, etc. From my recollection, when running poorly the motor was running on 3 cylinders (no ignition).

At some point, we the problem became intermittent. The motor would run fine only to bog on the next run. We then realized that shutting the motor off all the way (key all the way off) would almost always result in the motor running fine for a short time. After wiggling more stuff - the problem went away and has only reappeared once since. A quick shut down and re-start fixed it.

Now:

I am about to service the boat for this season. I would like to regain confidence in the motor, so I can take it off-shore. It seems that with the older motors it was always the stator or switch box. Because I don't have much free time to "mess" with the boat, on top of the yearly plugs and filters I was going to throw some parts at it. I was thinking a stator, trigger, and regulators. After a bit of reading, it appears that this generation of EFI is more complicated with more moving parts. Now I am not sure what to do, and could use some guidance. I have the manual, and a multi-meter, hand tools, and general mechanical/electrical knowledge. Please help me fix this so I can enjoy the boat again instead of stressing out!

Mike

Mike:

Start with the BASICS:

-Compression Test
-Spark Test (preferably WHEN the problem is occurring)
-Fuel Quality, Delivery, and Pressure Tests

One note: Multiple fuel filters are not recommended. Engine is already equipped with a spin-on separating filter, and adding additional inline filters can cause a fuel supply restriction.

Don,

Thank you for replying.
- Compression is good and even across all cylinders. I believe #6 was lowest at 115psi cold.
- When the problem occurred, best I could tell 2,4, and 6 had no ignition.
- I did not have a pressure tester when the problem occurred, but did test fuel pressure during operation and from what I remember is was within spec.
- When the problem occurred, I immediately changed both the OE spin on filter and the external filter. The problem persisted with no noticeable change. I also tried pumping the bulb while underway, and that made no difference as well.
- Fuel is REC90. To the best of my knowledge, the boat has never seen ethanol.
- I am aware that an external fuel filter is not recommended by Mercury, but based on my experience and empirical data - the high flow Rycor filter/separator I am using should not cause the problem I am seeing.

Best I can tell, I have an intermittent loss of ignition on 1 bank. What can cause this? What should I test?

Forgot to mention that I also opened up the vapor separator. There was no sludge or particulates in the separator. I cleaned the fuel pump strainer, but it really did not need it.

Ignition Controller, Detonation Controller, Grounds on the coil plate (for the CDM's), faulty CDM, kill circuit problem, or in very rare cases, knock sensor (just to name a few).

Make sure it's really 3 cylinders that have no spark.

Please keep posted on what you find out. I'm struggling with the same problem with a 2002 200 EFI. I have had very little time to troubleshoot. Compression is good, that's as far as I have got. Going to test fuel pressure and am figuring on having to pull the fuel system and have it cleaned. Mine never seemed to run better after having it shut off, but same exact problem as yours.

Don,

I can not be 100% sure about being 3 cylinders being down, because i was not very systematic in testing. My best assessment at the time, was no ignition on port cylinders. As another data point, the motor would run a max of about 1200 RPM in gear. Anybody know if that is about right for running on 3 cylinders? Obviously, it was about as smooth as a dryer full of bricks :)

Is there a way to test the ignition and detonation controllers considering the problem is intermittent? I will definitely check all the grounds. I plan to spend some time servicing the motor next weekend (filters, plugs, impeller) and am trying to come up with a game plan for troubleshooting. I am almost sure that the problem will not manifest itself on the hose (has not yet, only happens at the most inopportune time, far from shore). If I have time, I will have time to put it in the water and flog it for as long as I can. Please suggest anything I can test, wiggle, smell, etc :)

I will definitely update if I find anything.

I had a little time to work on the motor last night night. I changed the plugs and fuel filters. Just in case, I decided to open and clean the VST. The tank and the fuel pump sock filter were clean. Since I have never cleaned the final filter, I decided to clean it as well. I am glad I did, as it had plenty of gunk on it! Cleaned it with some carb cleaner and resealed everything.

Last season I had a problem with the motor oil tank not filling quick enough (starting with everything full, I would start getting the oil alarm beep after 30-45 minutes of running). I was pretty set on pulling the oil injection but decided to give the stock system one more shot. I pulled and cleaned the motor mounted tank, replaced a couple of oil lines that looked tired, and made sure everything was tight. I also installed a new oil cap since the old one was cracked.
When I pulled and drained the big external oil tank I found a bunch of sludge in it. The oil pickup screen was covered with this sludge as well. Anybody knows what can cause this? This is my third season with this boat and I have used Quicksilver Premium and Penzoil 2 stroke oil. I did not clean the tank when I originally got the boat, and do not know what the previous owner used.

I was running out of time so I threw everything together, connected the water hose, pumped the bulb, and turned the key. The motor started on the first try! I was out of time so I only ran it for a few minutes, but all cylinders were firing.

My plan for next time (hopefully next weekend) is bring the motor up to temperature and to start wiggling everything to see if I can reproduce the problem I had last season.
I will also do the link and sync. Can somebody confirm that the link and sync for this motor refers to the procedures outlined in Section 2C of the manual - Timing, Synchronizing and Adjusting? Is there anything else?

No mechanic but sounds like you are getting things in order nice.

The sludge will happen over time. I had the same when I cleaned my tank and use premium plus only. The clogged screen and cracked cap will keep your motor tank from being able to keep up, good find.

Did you disconnect the ECU harness and engine harness? Check them for loose pins, corrosion...etc Spread the pins a little with an exacto knife and apply a little dielectric grease

2C is link and sync but wouldn't think timing issues would cause an intermittent problem, if it was timing, it would bog, idle bad, no top end...etc all the time.

Hook up your timing light and look at it when you wiggle things around, it is easy to visualize. You can wire tie the trigger and set it down so you can use both hands on the motor.

Hope you get it worked out, stuck in the ocean would make for a horrible day(s).

Haughton, thanks for the feedback. When the damn thing would not run in the Bahamas, I messed with everything. Just trying to get back to a good baseline before I start jiggling all the wires :)

Section 2C is indeed the Engine Synchronization and Adjustment Section (use it for Sync-n-Link).

Make sure all settings ARE correct. This is critical- and can cause performance problems (potentially even intermittent ones, since this engine is equipped with a knock sensor).

Be sure to report back once you have REPLICATED the problem, and narrowed it down to a specific (accurate) cylinder or cylinders.

Spent a little time setting the timing, adjusting the linkages, and the TPS. Did not have a chance to pull the boat out of the garage, so no real troubleshooting.

Confirmed TDC, and .462 - only had to make a tiny adjustment to the pointer; probably could have left it alone.
http://media.fotki.com/1_p,rtdkbqfdq...16_5206-vi.jpg
Set base WOT and base timing. Set WOT at 24 deg BTDC. The manual recommends 0-9 deg ATDC for base, but I saw several mentions of 4 here on the forum so I settled on 4 deg ATDC. Is that a good baseline for my motor?

Also, should I be concerned about damage to the impeller since I did the timing setup dry (turning the motor with the starter, probably a total of 30 seconds)? My gut feeling is that it will be fine.

To set idle timing, I had to almost bottom out the adjustment screw. Does this look right? My idle timing was way off before the procedure, something like 6 deg BTDC.
http://media.fotki.com/1_p,rtdkbqfff..._192010-vi.jpg


Lastly, I set the TPS to .250. Is that a good baseline? Is there a rule of thumb for this?
http://media.fotki.com/1_p,rtdkbqffk..._190619-vi.jpg

Thanks!

4 ATDC is fine for idle/base timing.

Better check alignment of roller and cam. If they are DEAD-ON aligned, don't worry about the idle timing screw. Usually this is indicative of other "tampered" adjustments, though.

Can't set TPS in the garage without water. Engine must be up to operating temp, Port side temp sensors unhooked.

NEVER spin a water pump dry. I personally would be pulling it down and replacing the impeller (I've seen a brand new one trashed in under 20 seconds- dry).

A lot of white wire ties. Had a couple on mine when I put my reeds in and one crumbled when i tried to cut it.

Don,

I aligned the cam roller per the manual prior to setting timing, and it looked dead on to me. I verified that everything was still lined up after I finished with adjustments. The reason I ask about the primary pickup screw being almost all the way in is because my static idle timing was waaayyy off! Provided I measured everything correctly, before adjustment idle timing was well BTDC, and not ATDC as it should be. Any time I make a major adjustment like that, I try to double check. How would the motor run with base timing say at 6 deg BTDC? It always started well and idled ok. I did have an issue occasionally stalling when going from reverse to forward.

What do you mean tampered adjustments? What else should I check?

Setting TPS with a hot engine, is that something that I missed in the manual or a rule of thumb? I did have the temp sensor disconnected.

As far as the impeller goes, I was going to swap it out regardless but it is good to know that even starter speed can kill it dry.

Haughton, those white zip ties are fresh and should be good for a while :)

Engine will "run" with advanced timing, as you've already noted. Prefers to be around 4 ATDC for best idle quality/shifting.

"Tampered" means someone messed with them at some time in the past.

Engine must be up to operating temp when setting the TPS. Should be in the manual (may even be at the beginning of the section). TPS, IAT and CTS are all in the same ECU circuit.

Don, thanks for the clarification. I can get the engine to temp and adjust the TPS on the hose, right? There are a few more things I want to do before I splash it.

Yes sir. :thumb up2:

Replaced the impeller, got the engine started on the hose, got it up to temperature, and readjusted the TPS. The engine started instantly every time, idled great, and I was feeling good....until...

Day 1:
I took the boat to the Gulf. It was really windy and rough offshore so I put into a protected bay. Boat started right up and ran perfect for about an hour - maybe 35 mins of idling or low throttle and 15 minutes of cruise around 4K RPM. After an hour, it stopped idling. It would not re-start without some throttle. With a little throttle, it would re-start and if I could get it in gear fast enough it would run fine at cruise. Bringing it back to idle it would sometimes stall, and other times idle just fine. At times when it stalled, it was not an instant stall like turning the key off, but rather a stumble and stall over 1-2 seconds. The fish were biting, and so we anchored and shut off the engine. 30 minutes later, it would not restart at all. I tried pumping the bulb, and it was soft. I could not get it hard. The engine just spun with no signs of life. Fished some more and called for a tow.

Out of the water, I was able to find the following - 1. I had a loose fitting on the external filter/separator that was barely seeping fuel. 2. One of the batteries was low (really old - dated spring of 13).

I fixed the fuel leak, and still could not get the bulb to get hard. Took off the bulb, and checked that the fuel pickup did not have a restriction. No problems there (gas tastes bad and tingles). I had a spare bulb, so I put it on. I was able to prime the bulb and get it hard. Checked all other fuel connections and saw no more leaks. Bought and installed a new starting battery. Turned the key, and the motor started instantly! Ran on the hose for 30 minutes with no issues. Weather was getting better so decided to take the boat out again and take our chances.

Day 2: Put into a protected bay. Started instantly and held idle. Ran to several spots mixing cruise, idling, and shutting the motor off. After some time, started trolling at idle. After 15 minutes of trolling - the motor stumbled and shut off just like the day before. Restarted with a little gas and I turned around and started trolling against the wind at 1200 RPM. Went about 5-10 minutes and stalled. Would not re-start. Would turn over with no signs of life. I pulled off the cowling and wiggled everything I could think of, also pushed in the fuel check valve and fuel squirted out. I could hear the fuel pump running when I turned the key. Would not restart. No signs of life. Clearly either fuel or fire were missing. With my head low in defeat, decided to drift and fish for a while before calling for a tow. Fished for almost 2 hours, trying to start the motor every 15 minutes or so. At the 2 hour mark, the motor started and idled like nothing ever happened. Reeled everything in as fast as I could and jumped on plane. Ran fine all the way to the dock (4 miles or so). Put the boat on the trailed and went home with my tail between my legs. Getting frustrated to say the least.

Observations - problem is still totally intermittent. Engine never seems to die while on plane - dies while idling or low throttle situations, usually after coming off plane. Fuel issue is new and could be unrelated. I think I fixed it with the new bulb and tightened fitting. Have no clue what is causing the shut downs. May be the same issue I had last season but manifesting slightly differently.

I am hoping that the next time I go work on the boat, it does not start - so I can do some troubleshooting. Any suggestions?

I would carry a timing light with me and check each plug for spark while on the water and when problem occurring. Also would keep Digital meter to check battery voltage while problem occurring. Sounds like could be electrical problem, not providing spark or power to battery. Have you checked output at regulators? Or tested the stator to be in spec?