Engine misfires and speed fluctuations

[Kreiseltaucher]

Hello everybody My name is Peter and I live in Germany. Since three years I have two electrical problems that no one in Germany has been able to help me with. My engine is a 350 MAG MPI EC with PCM 09 built in 2014 1st problem = when I make tight right-hand bends, the engine has constant sawing speed fluctuations of 300-400 revolutions. This is not the case with left turns. No cables are squeezed by the steering. Fuel pressure does not change. 2. Problem = when I drive through waves, the engine stops very briefly every now and then. The speed then decreases by 400-500 revolutions. The warning horn occasionally sounds briefly at the same moment.
No Guardian errors are displayed in the Smartcraft Monitor. I also bought the Rinda software and read out the PCM. Apart from misfire on all cylinders, no errors are displayed. The speed fluctuations are clearly visible. At the moment, however, there are no eye-catching other parameters that could be used to pinpoint the error
Since the dropouts sometimes come with a warning tone, I have the idea that it is the same tone when you switch on the ignition. Which would mean that there is a fault in the purple colored cable from the ignition lock to the PCM. Or in the clean power cable. In my opinion, both should be recognizable in the Rinda software, which unfortunately is not the case. You see me pretty baffled and I hope someone of you has an idea where to look. Best regards Peter

 

[alldodge]

Howdy
Anything that sounds the alarm should be recorded in the PCM. It may not be in current faults but would be it the history. Look deeper with the Diacom software and see what you find

Also post a serial number

And GA_Boater can you move this to the Merc section?

 

[Kreiseltaucher]

It´s a CPO Engine, Serial No. 1G481589. My dealer said that I can also look at 1A623185 & up.
Ok, I will have a look in the history next weekend

 

[alldodge]

The 1G doesn't show up so using the 1A

Do you have digital or mechanical throttles?

 

[Kreiseltaucher]

Mechanical throttle

 

[alldodge]

Sure is a puzzler, thinking a loose connection
The alarm could be sounded if the drive lube bottle is low or if the float switch is messing up

 

[Kreiseltaucher]

That could be, but then the speed drops briefly and the alarm sounds only occasionally when the speed drops

 

[alldodge]

With the alarm only lasting for a brief second it could be many things. Some alarms sound and do not change the power like drive lube, Battery voltage low/high and many others. They can be 2 or 3 beeps each about a second long each beep, but with it only being quick its unknown

If bot has a vlotmeter see if it changes any, then verify voltage with hand held meter

 

[Kreiseltaucher]

Since the alarm only ever comes in connection with a drop in speed, but not always but maybe in 5% of the drops, I do not believe that it is a warning from the Guardin system or drive-lube. I can adjust the error by pressing the Laynard switch very briefly or briefly. With a very short drop in speed, with a short drop in speed and alarm. I have already changed the switch and the cable but nothing has changed. The same happens if you interrupt the clean-power cable. At the weekend I install a new clean-power cable.

 

[Scott Danforth]

how are you monitoring the fuel pressure?

i would have a mechanical gauge on it.

 

[Kreiseltaucher]

I also did it with a mechanical gauge