# Nilfisk E 140.3 pulsating / Starting and stopping randomly



## Karl-einarb (Mar 24, 2021)

Hello,

I have a Nilfisk E 140.3 pressure washer that starts and stops randomly.
I have searched a lot and tested all of the recommendations but none of them has solved it, so I am posting here hoping that someone has something else to test.

*What is the issue:*
The pressure washer starts _thunking_ when it starts, running for between 2 to 30 secs before stopping.
Then it wont run for a while before starting for a couple of seconds then stopping again, repeat.
It seems to run for longer if I use it as soon as it is starting, but it will stop either way.
When it has stopped working it does not always start when turning the power off and on again.

*Troubleshooting:*

All power cables are securely connected
None of the power cables has any damage to them
There are no visble or audiable leaks on the machine
I have tested giving it multiple water pressures
Replaced the Start Stop valve and greased the o-ring and the outside of the white part (Part.no: 128501513)
Replaced the microswitch (Part.no: 128500628)
Tried rotating the microswitch in case the piston would not interface with the switch correctly at some angles
Tried to run it without the microswitch connected, when I do this it is continually running and I can see the white piston going fast back and forth.
Tried to manually click the microswitch. The result is that it stops when not pressed and works when pressed. When pressed it works as it should all the time.
*Not tested theories:*

There might be something cabled incorrectly making it run when it should not and vice versa. I am not good with electronics so I have not attempted tampering with it.
I have embedded an image of the cabling below.
There might be something in the motor/pump not extending the piston when it should. I am not well-versed with motors so I have not attempted to open it.

Do anyone have any ideas of what to do next?
Any help would be greatly appreciated!


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## iowagold (Jan 22, 2020)

take a video of how it is acting up for us


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## iowagold (Jan 22, 2020)

make sure when you connect the water feed line that you purge the air out of the feed hose as well as the pump
by pulling the trigger with the pump power off.
make sure all of the air is out of the system before firing up the washer power.

the valve for the pressure bypass could have trash in it..
or a cracked valve leaking.
most washer of these little styles you replace the pump assy for this issue.

make sure when storing the washer pump for cold weather to have purged all of the water out of the pump and use pump saver foam in the pump inlet.


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## iowagold (Jan 22, 2020)

also take a look at this video
it shows there is a screen for the water feed.


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## Karl-einarb (Mar 24, 2021)

Thank you for all the tips Paul, I will check into all of this over the weekend.
I will let you know how it goes.


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## iowagold (Jan 22, 2020)

any time!
let us know and shoot some video for us to hear the issue!


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