2015 df250 slight vibration at idle and lower rpms

[Dbanni5]

2015 df250 105 hours. Developed a slight vibration at idle and won’t go above 5000rpm. Usually runs 6000 at wot. Check engine light not on. Any advice would be greatly appreciated.

[artdf175]

maybe a fuel problem
what I see is low hours for a 5 year old engine
probably have a decent size fuel tank but not cycling that much fuel through your tank
Art

[Dbanni5]

I just purchased the boat a month ago. . It had 1/2 tank of gas when I bought it. I filled the tank before dropping in water. Fished 3 times before problem started. Was at the last 1/4 tank when it started. Going back this week. Gonna fill back up add some stabile.

[tsturm]

In gear????

Or dinged the prop?

[Dbanni5]

I looked at prop. Does have a small ding that may have happened this weekend because the lake is flooded with lots of debris. Didn’t think it was enough to lose 1000 rpm

[Moonlighter]

How long since routine maintenance has been done?

Dropping 1000 rpm and rough idle, could be lots of things. Fuel being dirty and clogged up filters, or something simple like a loose spark plug lead or a bad plug.

You can pull the spark plugs to see how they look. If you have a water separating fuel filter, take it off and empty it out in a glass jar and see what you find.

May be worth getting a service kit if it hasnt been serviced recently and installing everything from the kit, at least that brings you to a known standard of maintenance and may solve the problem at the same time.

Or if you dont do servicing like that yourself, get it to an experienced Suzuki dealer, as this is the kind of problem that should be quickly identified using the Suzuki diagnostic software.

[Dbanni5]

The dealership I purchased from did the 100 hour maintenance the week before I took possession. I bought a 3 year service contract. Problem I have is it is in the water at my boat house. Most of the boat ramps are closed because lake is flooded.

[Moonlighter]

So how long has it been sitting in the water?

If its been more than a week, has growth started on the hull? Easy to lose a heap of rpm and speed with even a moderate amount of growth there...

But anyway check the spark plug leads are on firmly and the water separating filter can be drained as mentioned earlier, both are relatively easy to check.

[Dbanni5]

It’s on a lift.

[redlowrey]

The simplest and cheapest thing for you to do first would be to put a set of plugs in it, your engine has coil on plug, the vibration might be one cyl dropping out.
Simple to test remove the cowl run the engine and remove the coil connector from each plug one at a time, there should be a noticeable drop in rpm each time
you remove a connector, if one cyl does not change in rpm, you have located the cyl that is not firing.

If the rpm drop is the same for each cyl the problem is not a plug or coil, but make sure the vibration is there when doing the test.

[Dbanni5]

Ok. Did some checks. I have no voltage to the #2 coil pack. My guess is broken wire or bad ecm. Anyone seen this

[redlowrey]

Ok. Did some checks. I have no voltage to the #2 coil pack. My guess is broken wire or bad ecm. Anyone seen this

You will have b+ supplied to all the coils remove the plug connector turn the key on and have your test light connected to ground. you should have b+ on the gray wire, if you haven't come back an inch from the connector in case it has broken at the pin, if you still don't have b+ start tracing along the loom.

If you have b+ connect the test light to b+ and probe the black wire, it should light up, if it does crank the engine and test the blue wire it should blink, if it does it means the driver inside the ecu is connecting the ground to switch the coil on.

[Dbanni5]

Thank you. I have no b+ at any of the 3 wires at all. I have a warranty. Just can’t pull boat out of water because boat ramps are closed due to flooding. Will it hurt anything to run it like that for a few hours? Have to get some fishing in while I’m here.

[redlowrey]

The only wire that should have b+ is the gray wire, to do the other tests you need to supply b+ I don't think you understand, best bet to get an auto elect to have a look for you.
If you use the boat disconnect the injector wire to the cyl that is not working.

[Dbanni5]

I had no voltage at any of the 3 wires going to coil pack. But do have voltage at the #1 cylinder coil pack. Just not at #2. I was able to get boat out of lake and is at a Suzuki factory authorized dealer. Thanks for all of your help.