Map sensor pressure suzuki df 115

[Freddy jakob]

Hello. Questions about map sensor. Have used sds and found that the map pressure is low at idle about 10.38 inhg. Have not tested this at higher speeds since I am bothered that sds loses contact. Could map sensor be to blame for me struggling with high engine temperature.?

[Freddy jakob]

Slightly higher speed

[Freddy jakob]

Spark plugg 100 hr

[Moonlighter]

White spark plugs like that could, I believe, be due to incorrect fuel air mixtures causing hot running. So yes that MAP sensor could well be an issue contributing to the issue.

Time to get a experienced Suzuki mechanic involved if it were me.

Those plugs are telling part of the story, as is the overheating, I think that both of those are probably symptoms rather than the core problem, but its above my level of knowledge to say more.

[Freddy jakob]

Thanks for the feedback Moonligther I have had the engine diagnosed by a suzuki mechanic and he says everything is ok. But the spark plugs and engine temperature tell a different story

[Moonlighter]

Tag member Redlowery, he posted earlier on another thread. He is a gun Suzuki mechanic.

He will point you in the right direction.

[Freddy jakob]

Hello. I read the thread where Redlowrey took this with low map sensor pressure, which made me think of my map sensor. Is unfamiliar with tagging on the forum. Hope Redlowrey has time to drop by my thread

[Moonlighter]

Hello. I read the thread where Redlowrey took this with low map sensor pressure, which made me think of my map sensor. Is unfamiliar with tagging on the forum. Hope Redlowrey has time to drop by my thread

Find the thread he posted on, and tap on his name and send him a PM.

[redlowrey]

Mate a lean running engine will increase the combustion chamber temperature, but your engine having an 02 sensor can monitor the air fuel ratio and change the fuel trims till it exceeds it's limits and will bring the check engine light on. How the 02 sensor works it measures the oxygen iron content in the exhaust stream by producing a voltage between .1 and .9 of a volt, in cruise the computer will change the pulse width on the injectors to keep the air fuel ratio at around 14.7 to 1, .1 lean .9 rich, if for instance the fuel filter was restricted the engine would start running lean, the computer will see this by the 02 signal voltage being low, so it will start adding fuel till it runs out of limits and brings on the check engine light.

The plugs look ordinary, how long ago were they replaced, pull the plugs out that are currently in the engine and take a close up snapshot on them, your sds information looks alright on another post I looked at the absolute manifold vacuum reading but I didn't subtract the variation, I took it at gauge pressure, I should have woken up straight away when I looked at the injection pulse width. What was the reason for changing the 02 sensor, did the check engine light come on, or did you think that may have been the over heat problem.

For the over heat problem give some detailed information on the engine when it started, how long you have owned the engine and some history, describe the over heat problems that has been happening. Remember the plugs will stay light tan to white only when you cruise if you hammer the engine or under heavy load obviously they wont stay that colour, yours look like the engine has been hammered.

[Moonlighter]

Hello. I read the thread where Redlowrey took this with low map sensor pressure, which made me think of my map sensor. Is unfamiliar with tagging on the forum. Hope Redlowrey has time to drop by my thread

You haven’t yet said what year your engine is, and if its a DF115, or a DF115A series. The A’s replaced the older model in 2011/12 if I recall correctly.

Important to know this.

[Freddy jakob]

Thanks for the feedback Redlowrey and Mooligther. Bought the engine new and is a 115a 2014 and about 500 hours. Iac and ecm were replaced when the engine was 6 months old due to a fault. Since then, it has worked fine until January 2021. Then I got error code 3-6 o2 sensor. Replaced it with serial number 18213-98j30 the old one had no. 98j00. The boat was not used until the summer and then I noticed that the temperature increased to 78c ° when I went from 5000 rpm to 1000 rpm. Bought me sds and connected the motor but here I lose contact with the motor. Has exactly the same error with sds as member Supagruv.Redlowrey replied that there is a contact fault on the petrol pump or a diode in rectifiers but have not been able to check this out. The temperature is living its own life now. Sometimes it is at 67c ° when I go to the cabin and on return it is at the normal 60c °. Sometimes it gets hot about 79c ° when it is started and idles and sometimes it does not get hot. If I stop the engine and start it again, it goes down to 56c ° at idle. The engine runs mostly at 5000 rpm. It is only driven a few minutes at 6000 rpm. Seems mostly like there is something in the cooling channels that move see. The engine is nicely treated with zinc, oil and things like that. I have checked the compression, valves, all of the filter, changed thermostat, water pressure valve, complete water pump. The only thing I am left with is the gasket between water and exhaust inside the engine. If not the o2 sensor and sds problems are related. I also use torque wrench on spark plugs and everything else

[Freddy jakob]

One more thing is that when the speed is increased from 700 rpm to 1500/2000 rpm it becomes unstable. This is also noticeable when it is in gear. Unstable speed increase.

[redlowrey]

This is interesting, did it do this before your problem started or after. Does it seem like the revs go up and down evenly or does it feel more like an uneven splutter. The other member supaguv on one of his posts said he had electrical interference I was thinking if his rectifier had a shorted diode it would allow AC to sit on top of the DC and because his fuel pump was controlled by the computer it may have effected the duty cycle on the ground, that is why I asked him to supply an external ground to the pump, but he never come back with an answer.

I don't think that has anything to do with your sds dropping out, simple test connect your digital multimeter to AC run the engine and you don't want to see any more than 300mv at the battery, more accurate if you check at the rectifier.
Do a screen shot of the sds 02 sensor information at 2000rpm and put it up.

[Freddy jakob]

Thank you for your feedback. It can run nicely at 2000 rpm for a few seconds before it varies and stabilizes. It mostly goes down about 150 rpm. As far as I remember it has been a bit uneven but has become more noticeable now. Seems like electronics are affected by something. When I connect sds it jumps and all values show varies with error codes and high rpm high temp etc for a few milliseconds before it loses contact with ecm. SDS pops out faster when I increase the rpm. I have tried to settings on the pc so that the usb port is waiting for a break. I will test this as you recommend the next time I am on board and connect the sds so I will take a picture and post here so that you are updated. Thanks for the help so far Redlowrey

[Freddy jakob]

I found a video that shows a bit of the sds problem

https://photos.app.goo.gl/zroxCpbj6ttEuPnS8 [IMG]https://www.suzukioutboardforum.com/core/image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABQAAAAUCAQAAAA ngNWGAAAA/0lEQVR4AYXNMSiEcRyA4cfmGHQbCZIipkuxnJgMStlMNmeyD2d wmc8+sZgxYJd9ErIZFHUyYYD7fkr6l4/rnvmtl7+KitrqV/fq2Y5eLY3Z9S48eRLe7BmVZ9qhTLhQ0algzZWQOVKSsCF8OjAn wbxDTWFDUhPK/jMr1H6HE/IqRky2DyvCefuwItwZzodVoYRiLqMkVCXrwpJ9twZ+sgfDYEFY l8wIWxZ9uFf7zkallxlJh4YrLGsKjZ**7VGHhLqwgFUN45DGdb 8MeXGpgB4ABZdeDcpZEY51A+hyLKz4S1W4MQWm3AibWtgWmk6d yISa1pSdyWTOlLXVp0+eL9D/ZPfBTNanAAAAAElFTkSuQmCC[/IMG]

https://photos.app.goo.gl/zroxCpbj6ttEuPnS8

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