2012 DF200 V6 No power on acceleration from idle

[Pilbara]

Hi Everyone,
Sorry if this issue has been discussed before but have not been able to find anything.
Ive been on the water twice in the last two weeks and have an issue with the DF200.
Start the motor on the ramp and power up to planing speed and all is good. After an hour of travel at about 4000rpm I slow to idle and start trolling (approx 1000rpm). After 30 minutes decided to stop trolling and try to accelerate to full planning speed. I noticed the engine will not rev even with throttle wide open. By this I mean it tries to get onto the plane but hasn’t got the power. Engine seems to be firing ok but seems to be restricted. Returned throttle to neutral. Tried again but issue still there. Tried a third time but again as before but this time the engine shuts down when I bring the throttle back to neutral. Switch the ignition off and restart the engine. It fires up immediately. I again attempt to accelerate and this time it has full power and does not fault. One week later and the same happens again. No major fault codes accept an ‘abnormal shutdown’ and an ‘low voltage’ warning on the Garmin gmi10.
Can anyone offer any advice, would the sds software pickup any other errors of what happened?
Possible white wire or power issues? Have checked fuel and all good. Engine does not miss a beat when it is at WOT or accelerating after it’s been off for a while only when I return to idle for an extended period of time and then try to accelerate. Cheers for any advice.

[redlowrey]

Has it got a throttle cable or electronic throttle control also what did you do about your engine over heat problem.

[Pilbara]

Hi Redlowrey,
The unit has a cable throttle, no electronics involved. I'm sure its got to be an electronics issues or possibly even a battery issue, although I have had the batteries load tested, etc a couple of months ago.
WRT the overheat engine problem that was one I don't ever want to have again. It took over a year to rectify. I have the SDS software etc and was able to diagnose the problem to the starboard temp sensor indicating it was going over temp. Powerhead was removed and cleaned etc with the issue still there, this included replacing all temp sensors, etc. Finally no option but to drive back (1500km) to the dealer and get them to look at it. They did fix the issue but I do not actually believe what they told me they did. They indicated that it was a burnt impeller which I know was replaced new 5 hours before (besides it had the same issue with the old impeller), then they went on to say that the gasket at the base of the water pump that sits under the spacer plate was leaking in air at idle and required a sealant to stop it from happening. They referred to it as a 'dry gasket' as they found it. Anyway, the problem was fixed and now the temp never exceeds 65 degrees C at any rpm. This was only rectified a month ago. Im still constantly monitoring temperature (out of habit) whenever I go out but I believe that that issue has been resolved.
Now this issue from this new topic has only started over the last two weeks. It doesn't cause me to breakdown permanently but it doesn't give me much confidence when 100km offshore that I have to switch the engine off and restart it to get rid of the no power issue.
Im going to start by cleaning all the electronic terminals from the batteries, white wire joints, main switch, etc to see if that could make a difference. I'll post the outcome when done.

[Pilbara]

The ECM current download shows no outstanding issues or current error codes. I tried to attach it but doesn't seem to allow me to upload the file. If anyone is interested let me know.

[redlowrey]

Seeing it has a cable it sounds like a fuel problem,when it bogs down does it sit between 2500 and 3000rpm and sit there, or wont get that far.
Both the fuel pumps are controlled by the ecu
It controls and duty cycles the ground, when the engine was running at 4000rpm there would have been around 80% duty on the high pressure pump ground and when running at 1000rpm there might be only 20% duty on the ground.
When you open the throttle the fuel pump might be still at 20% output and not 100% , and when you turn the key off and back on the pump will go to 100% duty, just a hunch.

Have a look at the SDS and Look at when the problem occurred and see what the throttle position signal voltage was, what the map sensor signal voltage was, and what the shift position signal voltage was and come back with the results.
You should see that the throttle position signal voltage was near 4volts, map sensor signal voltage near 4 volts and shift position all indicating wide open throttle.
It might even tell you what the duty cycle was at the time.

[Pilbara]

I didn’t actual notice but I don’t think it gets to 3000 rpm but it does seem to not go above a certain rpm ie it goes so far and then no more no matter how much you open the throttle. It also seems like it needs to idle for a while. That is for a few minutes before it does it. Once it’s back to normal if I come if the plane back to idle and accelerate again it goes as normal to full power. But once it does error the only way to overcome it is to switch the ignition off. Wait for 30 seconds then start it again. It then has full power again.
WRT the SDS can I recall data if it doesn’t show any errors? Or do you mean that I need to record it doing this and look at the data afterwards? Thanks for the help.

[Moonlighter]

Red, this sounds to me like the neutral throttle switch on the engine is the problem

- eg runs fine at speed, but drop back to idle, probably change into neutral at some stage, put back into gear then go. If the NSS isnt working (loose, cracked etc) then the ecu isnt seeing the signal it expects for “in gear” so it limits rpm to 3000 as it thinks the engine is still in neutral.

Give it a wriggle by changing in and out of gear a couple of times and it makes connection again and all is good.

What ya reckon?

[Pilbara]

Hey Moonlighter great to hear from you again. When I get back on the water I’ll give it a try. Just as an FYI I have tried a few times when the issue arises that I go back into neutral then try again, generally after a few time of doing that the engine stalls and the only error on the gmi10s is unexpected shutdown. Is it possible that the filter in the vst could be dirty? I’m also going to have a look at the history in the SDS and see if I can see what Red indicated earlier and report back if I can see those details.

[Pilbara]

Looked at the sds and cant find any record of the events (power loss) happening, the last three error events still there were the old ones from the engine overheat at idle issue, which is now fixed. I guess I'll have to wait until I get on the water again and see if it faults and when it does hope it throws an error code and then logs it. Because I need to run at speed for while I cant attempt this in a tub to log the data and hope that it does it. Am I able to connect the SDS out on the water with the engine cover off and log data when running?
Ive attached ecm output in several screen shots if they help at all. Cheers.

[Moonlighter]

If the NSS is faulty it wont throw a code, its just that the ecu still thinks its in neutral so it restricts rpm to about 3000.

It does that by disrupting spark, restricting spark advance and restricting fuel supply. It can make the engine run like a race car with the pit lane rev limiter activated, if you push it hard to that limit. On acceleration, it seems somewhat doughy compared to normal.

If those symptoms sound the same as what you experience, then the NSS is a good bet.

I dont know enough about SDS to know if it shows gears being selected, but if you run it in the drum of water, change in and out of gear several times and see if it shows the gear being selected.

You could also inspect the NSS (on the linkages in the engine, starboard side) and see if it looks loose or signs of cracks etc. It is not an expensive or difficult part to replace.

NSS failures are not unknown, we do so them pop up here on this forum from time to time.

[Pilbara]

Thanks Moonlighter, I’ll see what I find checking for a faulty NSS, etc and I’ll report back what’s found.

[redlowrey]

The NSS was the first thing I thought of, but he said in his first post the engine seemed to be running alright, and it is a very notable cyl drop out when it happens.
Plus I think that model has a code for the NSS.

I can’t read the data from the sds on my phone I will do it when I get home I Am at Portland vic.

[Moonlighter]

The NSS was the first thing I thought of, but he said in his first post the engine seemed to be running alright, and it is a very notable cyl drop out when it happens.
Plus I think that model has a code for the NSS.

I can’t read the data from the sds on my phone I will do it when I get home I Am at Portland vic.

I hear what you are saying - when I was having similar issues though, it was only when pushed hard to the 3000rpm limit that the limiter kicked in and in my case, it was more a kinda surging than outright missing etc.

Its often hard to say exactly how the engine is running based on casual descriptions though...

[redlowrey]

Looked at the sds and cant find any record of the events (power loss) happening, the last three error events still there were the old ones from the engine overheat at idle issue, which is now fixed. I guess I'll have to wait until I get on the water again and see if it faults and when it does hope it throws an error code and then logs it. Because I need to run at speed for while I cant attempt this in a tub to log the data and hope that it does it. Am I able to connect the SDS out on the water with the engine cover off and log data when running?
Ive attached ecm output in several screen shots if they help at all. Cheers.

I cant read your sds sheets, but if you can find old data the new data should be there, and it will tell you what you need to know as far as all the inputs when your problem occurred, it will show you when you were traveling at 4000 rpm, and for how long you were traveling at 1000 rpm, and you will see when you opened the throttle and what the rpm was, what the map sensor voltage was, what the throttle position voltage was, neutral switch switch off or on, high pressure fuel pump duty cycle and so on, all the information right in front of you.

Low fuel pump output would be the same as having a blocked fuel filter, or when the throttle is pulled into the wide open position and the high in rush of fuel through the gauze filter in the vst does not happen.
The strange one is turn the key off, then on and it is fine, but in saying that I have had blocked fuel filters do that, when the pressure drops and flow stops a lot of the particles fall back into suspension.

The more I think of it, the more it sounds like a blocked high pressure fuel filter, when you were traveling at 4000rpm, the fuel pump output would have been around 80%, when you trolled for an hour fuel pump output around 20%, with a blocked fuel filter it will diminish the flow to the rail and injectors, so when you open the throttle there is not enough supply, this will explain why it stalled on you when you went back to neutral.
When you turned the key off and back on, fuel pump output will be 100% enough to push through the filter and supply the load. The reason the fuel pump is duty cycled is to extend pump life.

[Pilbara]

Hi Redlowery,
Thanks for taking the time to have a look. On my Sds latest version there is a menu item missing which in the SDs manual is designated as “history”. I believe that’s the one I need to trace what it was doing at the time to give you the correct feedback. I’ll keep trying but your suspicion around the high pressure fuel filter (vst filter I believe) sounds plausible, hence I’m going to pull the vst tank off and open it up to get to the 2 micron filter). I reply back with the outcome.