Problems with 405

[Marc Payne]

Hello everyone I'm new here to the Forum.I'm located here in lovely wine country Past Roble's Ca.
So I have a prochem 405 and the problem is it will stay running when turn oil water bypass turn to the left but when I let it go it runs but real rough then eventually die. I change the fuel filter and sprayed carburetor with cleaner but I'm confused because
It's only when I let go of the dial does it run rough.
so if there was something wrong with the fuel system or carb wouldn't do it with the bypass turn to the left or not?
Could it be my fuel pump? is there a way of checking.
Thanks

 

[Lee Stockwell]

Not fuel system or ignition.

Loose wire or connection to high waste tank sensor or temperature sensor most likely.

 

[Marc Payne]

I did bypass waste tank sensor.
Where is temperature sensor?

 

[Lee Stockwell]

Check the pair of wires (brown/purple if I remember) that go to the waste tank sensor.

 

[Marc Payne]

Yes..those are the ones I bypassed.
I ran a wire from to 2 posts inside
Plug
Still runs crappy.
But not sure temperature sensor and where that is.
Can I check that or bypass it to test if that's the problem

 

[Lee Stockwell]

You have a great machine. Go to Prochem website and print a manual for it which will include a wiring diagram.

 

[Lee Stockwell]

If there is a loose connection between those two wires it will do like yours.

 

[Lee Stockwell]

All shut down circuits end up at the coil.

Some interrupt the positive + side, others interfere with the negative -.

I believe yours is the former.

Double check oil level. Then run a jumper from a positive source (battery +, starter cable,or lug #2 on wire panel) to the + terminal on the coil.

 

[Lee Stockwell]

If machine runs you can safely do today's jobs. Make sure radiator and oil levels are good to start.

If problem persists we can deal with that next.

One can of worms at a time.

 

[Marc Payne]

Oil level and water are good.
The problem is no mechanic close by
And trying to isolate the problem so I can get through work today.
When you say run a cable to the terminal on coil what coil is that one

 

[SamIam]

Could be low pressure switch to they go bad more then high temp in my experience

 

[SamIam]

you can by pass those also with a wire to test

 

[SamIam]

That the low pressure switch

 

[Lee Stockwell]

I was trying not to confuse him with less likely causes, given the symptoms he gave.

The coil, size of a soda can, big wire in center goes to distributor. Two little posts, labeled + and - on either side of center. Near top of machine. Left side.

 

[Marc Payne]

I bypassed that as well by unplugging it and plugging it into itself..if that makes sense

 

[Marc Payne]

Ok.. that's what I thought I wanted to make sure so run a wire from top coil
To positive maybe on battery
What kind of wire..

 

[SamIam]

Also top off your radiator fluid if you look inside and don't see any water or fluid that could
Cause it not to run to

 

[Lee Stockwell]

If you have verified fluid levels, you can also clamp a pair of vise grips to the override switch so that the the weight of the tool holds the switch in the bypass position.

Good for today's job.

 

[Marc Payne]

I thought about that but I didn't want to do any damage but my oil and water are fine.
Can you elaborate on coil trick?
I also read about start stop relay on the left side of machine.

 

[Lee Stockwell]

Any wire

 

[Lee Stockwell]

A VOHM meter can help later

 

[Shane T]

Ok.. that's what I thought I wanted to make sure so run a wire from top coil
To positive maybe on battery
What kind of wire..

What Lee is saying will get you thought the day. Just remember to disconnect this wire from the battery at the end of each job.

 

[Marc Payne]

OK so the steps would be to run wire from positive to positive on coil
Then try to start machine whole letting go og oil water knob?

 

[Shane T]

Yep. What you're doing is bypassing everything else in the system, nothing can disrupt it.

 

[Marc Payne]

Thank you so much for help!
For today I will just hold knob to left
To get me through day

 

[JS41035]

A pair of vise grips. The larger kind work well. Just be very careful to not clamp down to much and break the switch. The weight of the vise grips will hold the switch in override.
When you are done for the day make sure that you diverted is in the right position also. It has a plate on the shaft that should be pushed against small micro switch button on left.

 

[SamIam]

You guys are Macgyver

 

[Lee Stockwell]

Out of necessity when you work with machines.

 

[Marc Payne]

So your advice Got me through today..you saved my ass
Thanks again.
Machine stayed running as long as
Water pump switch stayed to the left.
I can either bypass it and keep eye on oil and water or keep looking for solution too problem...Which I would rather do.
So I also noticed that temperature is not getting as hot..maybe 180.
Could the two be related.
I did take my bypass solenoid out
And cleaned it out good
Also strainer and orifice on rt side.
I read something about a temperarture sensor on
Water box..could that cause machine
Not to stay started and perhaps cause underheating.

 

[Lee Stockwell]

Two separate problems, but both need to be addressed.