2011 F50TLR (with 250 hours) idles rough

[rejesterd]

SOLVED: Replacing the sensor assembly resolved the issue.

I've owned the engine since the beginning of last season (April 2016). On my first trip out this year (April 2017), it ran extremely rough at first. I expected this, because I know the fogging oil needs to burn off. After a few minutes of running at almost full throttle, it started to behave normally again. It idles around 740-750, revs to 6000 rpm at full throttle with a full boat load, planes quickly like it always did last year, etc.

However, the idle is still rough. The engine is clearly more shaky than I remember it being last year before I winterized it. I don't notice the shake at higher speeds, but I can feel it when I'm at 1/3 throttle or lower.

Last year, I did not use engine tuner spray before I winterized it. I tried spraying a little combustion chamber cleaner in the air intake yesterday, but it didn't really make a difference. I'm wondering if I should just do a full cleaning as the can instructs. The only reason I'm hesitant to follow the directions exactly is because they tell you to change the engine oil after you spray. I'd rather not do that if I don't have to, because I've only gone about 10 hours since I last changed it.

I'm sure some of you have read my other thread where I also have problems starting up the engine after it sits overnight in cool/dry air (but starts up fine every time after the first attempt in the morning). Rodbolt has suggested that this is due to a problem with my link/sync. So I'm wondering if my rough idle issue is related to my morning startup issue in this way.

Other than using the engine tuner, what should I be looking at? If it's the link/sync, I guess I need instructions for that. The service manual I found doesn't mention anything other than checking the length of the throttle link rod. However, the manual I found is actually from 2004, so maybe there is additional info in the most recent one. If anyone has a link to the service manual for a 2011 F50TLR, I would be most grateful.

For reference, here's my most recent YDIS report from when the engine was started but not yet warmed up:

========================
Diagnosis,
,Code,Item,Result,Condition,
,13,Pulser coil,Normal,,
,15,Water temp sensor,Normal,,
,17,Knock sensor,Normal,,
,18,Throttle position sensor,Normal,,
,19,Battery voltage,Normal,,
,23,Intake temp sensor,Normal,,
,28,Shift position switch,Normal,,
,29,Intake press sensor,Normal,,
,37,Intake air passage,Normal,,
,44,Engine stop lanyard switch,Off,,
,49,Over cooling,Normal,,

Diagnosis Record,
,Total hours of operation,250,
,Code,Item,Occurred,
,29,Intake press sensor,245.4,

Engine Monitor,
,Monitor Item,Result,Unit,
,Engine speed,796,r/min,
,Intake pressure,44.42,kPa,
,Intake pressure,13.27,inHg,
,Atmospheric pressure,990.9,hPa,
,Atmospheric pressure,29.3,inHg,
,Ignition timing,ATDC 11,deg,
,Battery voltage (12-16),14.90,V,
,TPS voltage (0.5-4.5),0.982,V,
,Throttle valve opening (0-90),7.1,deg,
,ISC valve opening,51,%,
,Fuel injection duration,2.31,ms,
,Water temperature (below 90),41.0,°C,
,Water temperature (below 194),105.8,°F,
,Intake temperature (below 70),21.0,°C,
,Intake temperature (below 158),69.8,°F,
,Engine stop lanyard switch,OFF,,
,Shift position switch,ON,,
,Oil press switch,OFF,,
,Dual engine system switch,OFF,,

Data Logger[Engine operating hours according to engine speed],
,Engine speed,Time[h],
,- 1000 r/min,131.9,
,1000 - 2000 r/min,64.7,
,2000 - 3000 r/min,15.8,
,3000 - 4000 r/min,12.1,
,4000 - 5000 r/min,13.0,
,5000 - 6000 r/min,13.3,
,6000 - 7000 r/min,0.0,
,Engine hours,250,

Data Logger[Data comparison graph],
,Engine speed[r/min],Battery voltage (12-16)[V],TPS voltage (0.5-4.5)[V],Water temperature (below 90)[°C],Intake pressure[kPa],Oil press switch[0:OFF 1:ON]
,750,13.18,0.98,62.5,38.5,0,
,1800,13.70,1.25,59.3,54.3,0,
,1900,14.87,1.25,61.7,54.8,0,
,2550,14.79,1.37,61.7,58.2,0,
,1350,14.87,1.09,62.5,42.9,0,
,1750,15.01,1.23,61.7,51.8,0,
,1550,13.77,1.17,61.7,46.4,0,
,1600,15.01,1.17,61.7,46.4,0,
,1000,14.79,1.05,61.7,41.5,0,
,1000,15.01,0.98,62.5,35.0,0,
,850,14.79,1.02,62.5,40.0,0,
,1050,14.94,1.05,62.5,42.4,0,
,850,14.87,0.98,30.4,43.4,0,
========================


And here's a report that was taken after the engine had warmed up for 10 minutes or so:

========================
Diagnosis,
,Code,Item,Result,Condition,
,13,Pulser coil,Normal,,
,15,Water temp sensor,Normal,,
,17,Knock sensor,Normal,,
,18,Throttle position sensor,Normal,,
,19,Battery voltage,Normal,,
,23,Intake temp sensor,Normal,,
,28,Shift position switch,Normal,,
,29,Intake press sensor,Normal,,
,37,Intake air passage,Normal,,
,44,Engine stop lanyard switch,Off,,
,49,Over cooling,Normal,,

Diagnosis Record,
,Total hours of operation,251,
,Code,Item,Occurred,
,29,Intake press sensor,245.4,

Engine Monitor,
,Monitor Item,Result,Unit,
,Engine speed,738,r/min,
,Intake pressure,36.58,kPa,
,Intake pressure,10.91,inHg,
,Atmospheric pressure,990.9,hPa,
,Atmospheric pressure,29.3,inHg,
,Ignition timing,ATDC 9,deg,
,Battery voltage (12-16),14.90,V,
,TPS voltage (0.5-4.5),0.982,V,
,Throttle valve opening (0-90),7.1,deg,
,ISC valve opening,31,%,
,Fuel injection duration,1.81,ms,
,Water temperature (below 90),62.5,°C,
,Water temperature (below 194),144.5,°F,
,Intake temperature (below 70),33.3,°C,
,Intake temperature (below 158),91.9,°F,
,Engine stop lanyard switch,OFF,,
,Shift position switch,ON,,
,Oil press switch,OFF,,
,Dual engine system switch,OFF,,

Data Logger[Engine operating hours according to engine speed],
,Engine speed,Time[h],
,- 1000 r/min,132.7,
,1000 - 2000 r/min,64.7,
,2000 - 3000 r/min,15.8,
,3000 - 4000 r/min,12.1,
,4000 - 5000 r/min,13.0,
,5000 - 6000 r/min,13.3,
,6000 - 7000 r/min,0.0,
,Engine hours,251,

Data Logger[Data comparison graph],
,Engine speed[r/min],Battery voltage (12-16)[V],TPS voltage (0.5-4.5)[V],Water temperature (below 90)[°C],Intake pressure[kPa],Oil press switch[0:OFF 1:ON]
,900,14.72,0.98,62.5,42.9,0,
,900,15.09,0.98,62.5,42.0,0,
,900,14.94,0.98,62.5,43.4,0,
,900,14.87,0.98,62.5,41.0,0,
,900,15.01,0.98,62.5,42.9,0,
,900,14.87,0.98,62.5,42.4,0,
,900,14.79,0.98,62.5,42.9,0,
,900,15.01,0.98,62.5,43.9,0,
,900,15.01,0.98,62.5,42.4,0,
,750,14.79,0.98,62.5,35.5,0,
,750,14.79,0.98,62.5,36.0,0,
,750,14.94,0.98,62.5,36.5,0,
,750,14.79,0.98,62.5,36.0,0,
========================

The only thing that jumps out at me is that the throttle valve opening is the same for both reports, but the ISC valve opening numbers are different. I also see the ignition timing go from ATDC-9 to 10 to 11.. it jumps between those values when the engine runs. From what I read, that's normal, but maybe there's something else you all can see. Thanks in advance for any advice.

[rejesterd]

Replacing the sensor assembly resolved the issue.

[fairdeal]

glad to hear its fixed -

but what sensor assembly? the TPS? the MAP?

[rejesterd]

It's literally called "sensor assembly" in the parts list and in the service manual. It's for both pressure and temp.

[fairdeal]

dual sensor - interesting
wonder which was causing the problem -

the air temp and barometer values in your YDS printout look plausible

[99yam40]

post up a read out of motor idling with the new parts installed
cold and warmed up

[boscoe99]

dual sensor - interesting
wonder which was causing the problem -

the air temp and barometer values in your YDS printout [B]look plausible

Someone has been watching too much "mythbusters".

[dray0151]

Are the Atomspheric pressure which is at key on the air pressure at the location and the intake pressure which is the engine on running not supposed to be about the same assuming the boat went no where? Atom pressure 29.3 inhg dropped to intake pressure 10.91 inhg? on my thread the other day about this sensor I was led to think they should be about the same? It is raining here today so maybe I am soaked?????

[99yam40]

I had thought that there were 2 different sensors, but was corrected.
there is only one and it reads atmospheric at key on motor off and then once motor starts the intake is measured

[boscoe99]

Are the Atomspheric pressure which is at key on the air pressure at the location and the intake pressure which is the engine on running not supposed to be about the same assuming the boat went no where? Atom pressure 29.3 inhg dropped to intake pressure 10.91 inhg? on my thread the other day about this sensor I was led to think they should be about the same? It is raining here today so maybe I am soaked?????

The pressure sensor is typically referred to as a Manifold Absolute Pressure (MAP) sensor. Absolute pressure as opposed to gauge pressure which is what most typical gauges indicate. The difference is nominally 14.7 psi at sea level.

With the engine not running the pressure within the intake manifold is the same as the absolute pressure outside of the intake manifold pressure. The same pressure that surrounds the motor, the user and everything around them. What is referred to as atmospheric pressure.

When the key is turned on the ECU takes note of the atmospheric pressure and uses it, in part, to establish how much fuel the engine going to need to start. Let's say the pressure is 29.92" Hg. About 14.7 psi.

When the motor starts and is idling the throttle is mostly closed. The pistons are doing their best to pull air through the motor but the throttle is closed. So the pressure within the intake manifold is lowered. To about 10.91" Hg. The ECU knows the motor is running and now records this an Intake Manifold Pressure. It uses it again, in part, to determine how much fuel to deliver.

If and as the throttle is opened up, with the motor running, the intake manifold pressure will rise, as more of the atmospheric pressure is allowed to get into the intake manifold. As the pressure rises the ECU knows about it via the pressure sensor and takes action to deliver more gasoline.

In another lesson we will discuss how the intake manifold pressure is plumbed to the fuel pressure regulator so that fuel pressure is made to rise and fall with the rise and fall of the intake manifold pressure. At a one to one ratio.

[dray0151]

So my question still is would it normally start to equal out as the throttle opens? On my F115 it was not reading differently that I know of , at any point in time?

[boscoe99]

So my question still is would it normally start to equal out as the throttle opens? On my F115 it was not reading differently that I know of , at any point in time?

As the throttle opens, the pressure rises within the intake manifold. It gets closer and closer to atmospheric pressure but will never be equal.

For a reason. What is that reason?

[dray0151]

Okay this is why I come here to get my masters in boat knowledge, I am glad some of you are more than willing to educate.

Reason may be only so much air mass can be pulled in through the throttle openings and requires a certain amount of fuel to combust at optimum, the ECU figures that and regulates the fuel pressure and there by flow and combustion. Pressure at or above atmospheric pressure would be way to rich of a mixture?

I await the continuation of my education.

[pstephens46]

As the throttle opens, the pressure rises within the intake manifold. It gets closer and closer to atmospheric pressure but will never be equal.

For a reason. What is that reason?

Where is Bernoulli is all of this? I thought when velocity of air increases pressure drops?

Now I'm fixing to get my ass handed to me...
Let it roll!

[rejesterd]

dual sensor - interesting
wonder which was causing the problem - the air temp and barometer values in your YDS printout look plausible

I would say both. The last cold reading I took on Saturday, the temp was 8 degrees off. The pressure was 1inHg off, and has always been off (either too high or too low).