Mystery Pressure Washer - trying to fix it up

[carbon]

Fuel pump drive internal should be D shaped on the fuel pump end all the way to the end of the plastic coupling. If its not then the fuel pump has seized at some point and the drive has failed rather than damage the fan

 

[carbon]

Wiring diagrams for steam cleaners can be a bit spread out. Sometimes if you're lucky they are inside the control box, which makes life a lot easier.

 

[the snooper]

i think you need to check for a spark to indicate that the power is getting to the coils and stick a meter on the solenoid wires and watch for a voltage appearing 5 seconds after the trigger is pulled

 

[carbon]

Check for mains voltage between terminal 14 on the main contactor and neutral. If that's ok check for voltage across the primary of the ign coil. if theres no voltage there then the filter z3 may have failed.

 

[the snooper]

Check for mains voltage between terminal 14 on the main contactor and neutral. If that's ok check for voltage across the primary of the ign coil. if theres no voltage there then the filter z3 may have failed.

also worth checking the flow switch as it will be that, that starts the timer off

 

[Cret]

Wow! This has been busy while I was outside again!!!

Great to have wiring diagram too, thanks.

Well, I'm delighted to say we're in business. Almost anyway. I've got the burner 'trying' at least now and it was a fuel flow issue.

My suspicion about the coupling being worn inside was bang on. I measured how far in it would get with the coupling pushed as far as it could go onto the pump (ie so it wasn't slipping), and as mentioned it meant the lugs only just engaged in the drive holes, or rather only about half the length of the lugs. This means that with vibration then the coupler can work towards the drive end then just spin on the pump shaft. I did a bodge of extra thick superglue and catalyst into the coupler then quickly fitted it as far as it would go so it was engaged as good as it could be on the pump shaft.

Refitted it, and leaving the supply pipe to the burner detached I fired it up. Sure enough, this time, after 5 seconds or whatever, thick yellow foul looking fuel spat out of the pipe where none had come out previously.
Quickly released it, then bolted up this feed pipe to the burner and tried again. It should now have clean fresh fuel coming through but it's possible some of the old stuff is still working through the pipes. Should have let it squirt into a tub actually until fresh clear stuff ran through. Doh!

Now the burner 'sort of' fires up, ie there is smoke from it constantly (grey, not sooty black, so not running rich), but the water is not getting hot (maybe lukewarm at best), and every now and then a big cloud comes out of the exhaust (see below!).
So it's not burning correctly but is at least trying. I think it's a matter of adjusting the electrodes etc now (or replacing them since they're a bit eroded) then adjusting until it burns nicely.

So my intention of getting it working tonight is kind of accomplished, with help from you helpful folks, thankyou.

Getting there.....

 

[the snooper]

Great stuff can't beat getting stuff going again

 

[carbon]

What sort of filter is in the back of the nozzle. If its a mesh screen then they clean ok. If its a sintered metal filter they don't clean at all well.
An other thing to try first though. Remove the black cap from the fuel pump. You should see a slotted screw turn that clockwise in small increments and test each time. You want more pressure to get a more efficient burn but not to much fuel that creates black smoke. A little bit of black smoke when just igniting is ok. When its burning better the water will get hotter quicker.

 

[carbon]

If its igniting ok then the electrodes are fine, its just a fuel pressure issue

 

[Cret]

The nozzle filter is a goly coloured close bunched affair, rather than looking like mesh as such. From googling the sintered type I'd say it's that. So it might still be clogged you think?
I haven't actually done any sort of alignment yet on the electrodes though, just cleaned out the nozzle assembly yesterday so they could be way out. I'd expect perhaps a sooty burn though if it wasn't igniting right in that respect but I'm no expert on this stuff so could be way off with that.

No sign of soot though, it's pale grey smoke from it, continuously there, but just with the odd big guff of it say every ten seconds or something.
I presume it must be continually burning since it constantly has some smoke, so not sure why it does the odd burst of smokescreen.

Will have a look at the fuel adjustment but would the electrode positioning/wear be something that should be properly set 'before' messing with the fuelling?

 

[carbon]

If fuel is going in and being ignited straight away then there not far out, if the fuel is going in then taking a couple of second to ignite it can be fuel pressure or electrodes in the wrong position. A bit tricky to explain but from the description and the picture you posted earlier more fuel pressure would help. If the fuel pressure is already maxed out then a replacement nozzle would be my first place to start. If the burner nozzle filter is restricted, the burner usually starts ok then after a short while reduces in output. The tone of the burner changes is the easiest way to describe that.

 

[Cret]

Thanks Chris

So tonight's report. I tweaked the pump output like you suggested. It had quite a lot of adjustment left in it from where it was, so I gradually increased it clockwise until I found it ignited properly instead of just smoking without the obvious 'woof' as it gets going (same as on my boiler). It's now adjusted most of the way up, but not quite fully as that caused too much smoke.
The odd thing with the smoke is at no point has it changed its colour at all - it's always grey, but it has just varied in density according to the pump adjustment. Didn't get anywhere near to being sooty or black in the slightest even at full adjustment, just lots more of the grey smoke. Would this be indicative of a partly blocked nozzle perhaps? I.e. that even at full adjustment it will smoke a lot, but not to the point where it turns sooty?

Anyway, once I'd messed about with this til I was reasonably happy, I let it run for a bit and sure enough it gets nice and hot. I turned the pressure down but while it gets hot enough that you wouldn't keep it on your hand for long it doesn't seem as hot as it perhaps should be for what's on the dial. I don't mean sticking my hand directly over the nozzle, but in the 'bounced' jet off the ground at point blank, if that makes sense?
I've got an infra red temperature gun (although it's lent out) so it'd be interesting to test the output and see what temps it actually is for the positions on the dial. Perhaps that could be one way of fine tuning the burn, eg at it's optimal fuelling it's perhaps giving more heat, so I'd get hotter readings. Could be an easy way to test this maybe.

It gets pretty hot anyway, so the burner is igniting at least now and we've made progress thanks to your suggestion.

Next, I turned attention to the tap for the detergent tank. I pulled the clunker and tube out of the tank, then with the tap fully on and fully off, I blew down it and it bubbled the water in the cistern both times. Ergo, faulty tap.
So I stripped it down and found 1 o-ring and another smaller square section o-ring. Didn't have a square section one so I used a normal one and replaced both of these, and added a bit of grease. Also cleaned & smoothed the inside where they seat. Once reassembled I can just about blow through it slightly when it's closed, but only a touch, so it's a big improvement. Hopefully this means it won't just guzzle through the detergent whether it's turned on or off.

As a test then, I mixed a load of fairy liquid (probably completely the wrong thing to use even for a test) and filled the tank. The washer seems to have a bit of a mind of its own as to when the soapy stuff was coming out - I'll look through the manual though to check the specifics of using it as I'm sure it will be a combination of the flow tap for it, and something else, like using low pressure etc.

It's getting there though.

 

[carbon]

If its not been burning correctly for some time the boiler does tend to accumulate diesel inside. Not huge qualities but enough to coat everything. This can take a while to burn off, which usually results in light coloured smoke. Continued use should see the quantity of smoke reduce. From experience this can take anything form 30 mins to a few hours. Taking the boiler apart and cleaning the burner coil and casing doesn't seem to make much difference.

 

[Cret]

Ahh ok - I won't worry about that then - will just find excuses to use it to see if it gradually improves.

One other thing was that last night and tonight at some point (I think after I'd already used it a bit), it wouldn't output any pressurised water (just a tiny trickle instead) until it had run by itself without the trigger pressed for a good few minutes.
I presume it is doing this to build up pressure in the pump but I didn't check what was on the gauge, just noticed that when it was working ok the gauge was at around 80 bar.

 

[carbon]

If contaminated fuel is used with steam cleaners that clogs the fuel filters and the burner nozzle and is left in that state for some time then the results can be a bit different



Possibly after one hour or it may have been two this was running ok again, after fitting a new nozzle and some adjustments.

 

[carbon]

Shouldn't really take any time to build up any pressure as water isn't compressible. Check that water is entering the header tank in the machine as quick as its pumping it out. If your water supply cant keep up or a inlet filter is blocked then the pressure will drop and it can take a while to get water back into the pump a they aren't designed to pump air. Running the pump with out water can lead to pressure seal damage.

 

[Cret]

Good point - I haven't checked the inlet filter you mentioned.
I presume from what you describe it must be suffering a pressure drop now and then, then getting water back into the pump. The header tank always has water in it though, and this behaviour I've mentioned is quite different to what happens when I use on full pressure and the header tank gets low. With that, it's obvious you need to just stop for a minute and let the header tank fill a bit more so you release the trigger and it stops running, then resume once the water has topped up. It then resumes the instant you try it.

What's happening though with this other behaviour is that it will run the pump without the trigger being used, and will run for a few minutes without being able to be used, despite the header tank being full. Then it will shut itself off once it's decided it's ready, and I can begin using it again.

It's done this twice since I began trying to get it all fixed up - once last night, and once tonight, and it will not emit pressurised water while it's running like this by itself.

Hope that description makes some sense!

 

[carbon]

Does this happen when in use or when you have released the trigger?

 

[carbon]

When releasing the trigger the machine should stop not continue running. Does it sound like the motor is labouring and running under load?
In the pdf spare parts and wiring diagham.
On page 22 check that the 'o' ring '3' is in good condition or that there's not some debris holding that small value '4' open.

 

[carbon]

Also check for debris between parts '3' & '4' on page 24. If the valve doesn't unscrew in one piece, take measurements of the nuts etc before dismantling it.