2006 SUZUKI DF140 4 STROKE stall

[redlowrey]

As you stated in your first post, when it is cold you can start it and it will run, but when you turn it off you cannot start it, is this correct. If so start the engine when it is dead cold, run it for ten minutes then turn it off and remove the plugs. Have a look at them and see if they are black with soot, if so remove the map sensor and make sure the little hole in the manifold is not blocked. When you turn the key on when the engine is cold, the ecu is looking at the cyl head temp sensor and the exhaust manifold temp sensor signal voltage so it can calculate the pulse width modulation for a cold start. It is also looking at the map sensor signal voltage, the voltage will be a bit over four volts and as the engine is being cranked manifold vacuum will change the signal voltage, if the hole is blocked or you map sensor is not working properly it will inject more fuel than is needed. it should bring on a code, but it might not be.

[Randys]

i will try to determine where that engine holder is and try to remove the lower cowl but i did start it cold with the upper cowl off then shut it off and tried to resart no go but i will look closer i have a shop manual i will look at.

[Randys]

okay i will check into but the plugs were pretty clean, and no codes but i will get a mechanic to look into this further thanks you all for your time.

[Moonlighter]

i will try to determine where that engine holder is and try to remove the lower cowl but i did start it cold with the upper cowl off then shut it off and tried to resart no go but i will look closer i have a shop manual i will look at.

When you take the side covers off, the location to look at is just above the hose connector for the fresh water flushing connector. Looks like a welsh plug, about an inch across.

[Grumpy56]

Starts when cold but not when warm? Don't these engines have a history of vapor lock issues? Does the fuel bulb stay firm when you try to restart it?

[Randys]

Okay so as i mentioned then engine will not re start right after you start it when its cold but also found out there is no spark when trying to restart it does this help?

[simon-666]

I have a very similar problem with my DF140.

Was working fine then suddenly get an engine warning light while at idle. Code flashing is 3-2. (MAP sensor pressure not changing)

The MAP sensor hole is fine and blown through with carb cleaner, and the sensor has been vacuum tested and responds according to the manual. Another sensor has been borrowed to confirm.

Engine is a pig to start.
Once running it idles like a bag of crap. any attempt to open the throttle will usually stall the engine or result in pops and backfires in the inlet manifold.

Plugs go black and sooty after a few mins of running. Prop exhaust is sooty too.

If the motor is stopped it will not restart without disconnecting the injectors and turning over a few times to clear itself out.
Seems to be over fueling to me?

Tested:
Fuel pressure (37psi)
MAP Sensor
Injectors removed and tested by a spe******t, all fine.
IAC working and cleaned.
Compression tested, all cylinders at 175psi.
Both coils tested, healthy spark.
Both fuel pumps removed cleaned and tested.
New set of plugs.
Another ECU has been borrowed and still the same problem.

SDS software reports all other sensors working and reading correctly.

Totally lost now. I cant get anyone to look at it for me in the next 10 days and supposed to be taking the boat on holiday in 2 weeks

[Moonlighter]

I have a very similar problem with my DF140.

Was working fine then suddenly get an engine warning light while at idle. Code flashing is 3-2. (MAP sensor pressure not changing)

The MAP sensor hole is fine and blown through with carb cleaner, and the sensor has been vacuum tested and responds according to the manual. Another sensor has been borrowed to confirm.

Engine is a pig to start.
Once running it idles like a bag of crap. any attempt to open the throttle will usually stall the engine or result in pops and backfires in the inlet manifold.

Plugs go black and sooty after a few mins of running. Prop exhaust is sooty too.

If the motor is stopped it will not restart without disconnecting the injectors and turning over a few times to clear itself out.
Seems to be over fueling to me?

Tested:
Fuel pressure (37psi)
MAP Sensor
Injectors removed and tested by a spe******t, all fine.
IAC working and cleaned.
Compression tested, all cylinders at 175psi.
Both coils tested, healthy spark.
Both fuel pumps removed cleaned and tested.
New set of plugs.
Another ECU has been borrowed and still the same problem.

SDS software reports all other sensors working and reading correctly.

Totally lost now. I cant get anyone to look at it for me in the next 10 days and supposed to be taking the boat on holiday in 2 weeks

Simon, this may sound weird but....

These engines rely on a strong power supply to the ECU. If they dont get it, they can, and do, do really weird things and will not run properly.

Given that you've clearly checked and cleaned nearly everything else, have you checked the white sub-battery wire that should be connected to the battery + direct or to the positive side of the master battery switch? And while there, check the main battery cables themselves for corrosion, the terminals for cleanliness and tightness and batteries for charge. And the main fuse for corrosion. And any harness connections, check for corrosion in the connectors.

[redlowrey]

I have a very similar problem with my DF140.

Was working fine then suddenly get an engine warning light while at idle. Code flashing is 3-2. (MAP sensor pressure not changing)

The MAP sensor hole is fine and blown through with carb cleaner, and the sensor has been vacuum tested and responds according to the manual. Another sensor has been borrowed to confirm.

Engine is a pig to start.
Once running it idles like a bag of crap. any attempt to open the throttle will usually stall the engine or result in pops and backfires in the inlet manifold.

Plugs go black and sooty after a few mins of running. Prop exhaust is sooty too.

If the motor is stopped it will not restart without disconnecting the injectors and turning over a few times to clear itself out.
Seems to be over fueling to me?

Tested:
Fuel pressure (37psi)
MAP Sensor
Injectors removed and tested by a spe******t, all fine.
IAC working and cleaned.
Compression tested, all cylinders at 175psi.
Both coils tested, healthy spark.
Both fuel pumps removed cleaned and tested.
New set of plugs.
Another ECU has been borrowed and still the same problem.

SDS software reports all other sensors working and reading correctly.

Totally lost now. I cant get anyone to look at it for me in the next 10 days and supposed to be taking the boat on holiday in 2 weeks

I assume you have tried running it with the cowling off, sounds like a classic engine holder problem. Take the map sensor off and connect a vacuum gauge to the manifold, hook your vacuum pump up to the map sensor and a digital multimeter to the signal line wire white, turn the key on and note the voltage it should be around four volts, pump the vacuum pump so it reads about three volts then start your engine and see how it sounds , if it is still rich give it a little more vacuum. This test is so you can regulate the fuel injection pulse width, if there is nothing wrong with the engine you should be able to get the engine to run smoothly just from changing the signal line voltage with the vacuum pump. Check and see what the vacuum gauge is reading on the engine.

[redlowrey]

Okay so as i mentioned then engine will not re start right after you start it when its cold but also found out there is no spark when trying to restart it does this help?

Hook up a digital volt meter to the gray wire on the ignition coil connecter, turn the key on and see what the voltage is. Use a thin needle so you can push it into the plug connector, also do you hear the fuel pump come on when you turn the key on.

[hopefrog]

Randy have you ever figured your problem out. We are having a very similar problem with our 2002. We have spent nearly $2000 and still not resolved. We have replaced ecu and it worked fine for the mechanic at the dealer but failed pretty quickly the first time we took it out.

It seems to be electrical or a sensor or something. We are stumped.

[Randys]

When you take the side covers off, the location to look at is just above the hose connector for the fresh water flushing connector. Looks like a welsh plug, about an inch across.

Moonlighter sorry about the delay in getting back, I have had this thing into 3 Suzuki shops over the last 4 mos yikes and no success not sure if you recall the story, but you mentioned I should check the engine holder corrosion which it looks like they guys didn't check because its rusted in,and I cant remove it. It doesn't look compromised on the outside. I guess we will need to get it out? I can start the engine onse and sometime multiply time but only by using the throttle lever and sometime it still wont start until I leave it. I guess I will leave the lower engine covers off and try that? I did try with the top off and that didn't help?

[Moonlighter]

Moonlighter sorry about the delay in getting back, I have had this thing into 3 Suzuki shops over the last 4 mos yikes and no success not sure if you recall the story, but you mentioned I should check the engine holder corrosion which it looks like they guys didn't check because its rusted in,and I cant remove it. It doesn't look compromised on the outside. I guess we will need to get it out? I can start the engine onse and sometime multiply time but only by using the throttle lever and sometime it still wont start until I leave it. I guess I will leave the lower engine covers off and try that? I did try with the top off and that didn't help?

Hi again!
If the engine holder isn't corroded through so that gases can escape from the exhaustion, then I'm afraid that won't be the problem. Taking the top cowl off simply lets that gas escape to the atmosphere and keeps fresh air going to the inlet manifold, so the engine will then run better. And taking the side covers off is really just necessary to get a good look at the plug where the corrosion happens, that's all.

I would suggest a close look there just I case there has been some heat escaping thru a pinhole and may have possibly damaged some nearby wiring. Although I think by now you'd have noticed that.

The fact that you can start the engine b using some neutral throttle suggests IAC valve issues. Have you had that checked out?

See also my earlier post a few above here to Simon regarding the white wire, battery and engine wiring harness. Well worth a look in that direction, too. If the ECU isn't getting good voltage all sorts of bad things happen.

[Randys]

Hi again!
If the engine holder isn't corroded through so that gases can escape from the exhaustion, then I'm afraid that won't be the problem. Taking the top cowl off simply lets that gas escape to the atmosphere and keeps fresh air going to the inlet manifold, so the engine will then run better. And taking the side covers off is really just necessary to get a good look at the plug where the corrosion happens, that's all.

I would suggest a close look there just I case there has been some heat escaping thru a pinhole and may have possibly damaged some nearby wiring. Although I think by now you'd have noticed that.

The fact that you can start the engine b using some neutral throttle suggests IAC valve issues. Have you had that checked out?

See also my earlier post a few above here to Simon regarding the white wire, battery and engine wiring harness. Well worth a look in that direction, too. If the ECU isn't getting good voltage all sorts of bad things happen.

Hello,

Okay when I Googled the issue there were people that had the same problem and said the you cant tell by looking at the plug that its inside and that the problem will only get worse because they used a steel plug to go in and aluminum housing? They said it very common. There is no damage to any wiring. I found out I can start the engine pretty much anytime by putting the throttle lever up all the way. put not something I want to go out in open Ocean with... missed the whole year with it super frustrating.

[Randys]

Hook up a digital volt meter to the gray wire on the ignition coil connecter, turn the key on and see what the voltage is. Use a thin needle so you can push it into the plug connector, also do you hear the fuel pump come on when you turn the key on.

Okay thanks I will try that yes the fuel pump is working.