Df140 dying after sudden raising rpms difficult to restart

[skelpie]

Hi
I'm Bartko from Poland. I'm dealing with 2009 suzuki df140. My problem started some weeks ago.

Starting of the engine looks natural (after first try). Idle - smooth and stable. When putting on gear also nothing wrong. Forward/backward on lowest rpms ok.

Problem is when i accelerate or pull the rpms/throttle lever. When i'm doing it faster, the engine wait just for a half second, then even dies or goes higher rpms. Last time in most cases the engine dies. I cannot restart it again just after stall. I found that i can restart the engine when i pull the rpms/lever above half way up The engine starts on high rpms then when i lower the lever runs back smoothly on idle.It's quite annoying especially during docking.


What have i done till now?

- first i go the IAS valve way - i've cleaned it then i replace it - nothing changed, except in my opinion the restart is easier.

- i've checked spark plugs - cleaned,

- i've checked the fuel from prime bulb to fuel pump/filters

- i've replaced the fuel line from tank to engine.


What else can it be?

Please help. My boat is grounded and in Poland weahter is beautiful now. HELP!

[catacom225]

Bartko, Are the any error codes or flashing , You will need to have the IAC tested, sounds like your describing a flat spot, the possibilities for troubleshooting are many, like valve timing,bad injectors or injector seals,vacuum leaks [ air fuel mixture ] bad fuel , where the plugs dirty,try replacing the spark plugs as mabey one is bad to start with and work you way through

[skelpie]

Like i've said - IAS was replaced - no changes.
One thing is quite strange. When i bypass the control box, and open the throttle directly from the engine by hand - rpsm rises normal without dying ?!?
Cheers

[Pappapetey]

Did you ever find the solution to this problem you were having?

[Murray]

If I had to guess his issue was with the throttle cable based on post 3. He hasn’t been on the site since 2019 so I wouldn’t expect a reply.

[Pappapetey]

Thanks Murray... I was asking because I have a sorta similar problem with my df140. Would you mind giving me your thoughts on my issue? Here’s my post
Hello my name is Pete and I currently have a 2003 df140 being worked on that I acquired from a family member that was not running (sat for a long time in a barn) it now has a new ECM installed along with a new voltage regulator, fuel pump, spark plugs, injector cleaning, fuel filter. It now starts and will idle fine but not go into higher RPMs without a lot of hesitation and fluctuation in RPMs and then will also die if put into nuetral too fast then takes a while to restart...it has a MAP sensor code but the shop states that the MAP sensor is performing as it should? Would love some insight since the shop it is at is running out of answers and confidence. Does a new/used ECM replacement need to be re-flashed?

[Murray]

https://www.suzukioutboardforum.com/...fetch?id=44612

What was the MAP sensor code? MAP sensor 1, a 3-4 code will put the engine in fail safe mode and act much like your describing. I gather this shop is not a Suzuki shop otherwise they would have put it on a computer and run the SDS(Suzuki Diagnostic System) See above link, you have 2 MAP sensors. As far as re-flashing the ECU I’m not sure but I don’t think it’s possible. I haven’t come across anyone on this forum that has re-flashed the ECM but I could be wrong. How’s the battery? A weak battery has been known to cause all kinds of weird occurrences and false codes.

[Pappapetey]

The current code that it has is 3-2 and just for more info this is the 4th ECM that has been installed because the original ECM (33920-92J10) had a 4-3 injector code and would not run with it in, the 2nd ECM was intsalled and motor ran but then later had a (3-4 & 3-2 code) so that ECM was then replaced with another but a different part # (33920-92J51) and that one had a code of (2-2 & 3-2) so this newest ECM now only has the 3-2 code and the shop is stating that the MAP sensor is performing as it should and is only equipped with one sensor? Does the ECM part numbers make a difference because I was told that it supercedes?

[Murray]

4 ECMs sounds fishy. If you scroll up to the top of this page to “Buy Suzuki Outboard Parts” find your part then scroll down to the bottom of the parts page and you will find a list of other engines that use that particular part and associated VIN numbers. The ECU is in the PTT section. This shop your dealing with, Is it a Suzuki shop?

[redlowrey]

The current code that it has is 3-2 and just for more info this is the 4th ECM that has been installed because the original ECM (33920-92J10) had a 4-3 injector code and would not run with it in, the 2nd ECM was intsalled and motor ran but then later had a (3-4 & 3-2 code) so that ECM was then replaced with another but a different part # (33920-92J51) and that one had a code of (2-2 & 3-2) so this newest ECM now only has the 3-2 code and the shop is stating that the MAP sensor is performing as it should and is only equipped with one sensor? Does the ECM part numbers make a difference because I was told that it supercedes?

There is only one map sensor, and it can give out two codes, remove the cowl and start the engine and see if that improves the way it runs. There may be a hole in in the engine holder beside the plug that you remove to screw in an o2 sensor. It will leak exhaust, and with the cowl on the engine will suck in exhaust gas which it can't burn, manifold vacuum will drop, map sensor signal voltage will rise, and engine will start running ruff and the check engine light will come on.
Start there, and come back on the forum with the results.