fuel/oil safty switch connection

[gospo]

Hi guys,
can you help me please and show a diagram where should goes cable from fuel safety switch?In mine there is closed outlet and I know that there should be some pipe/cable but no idea where it should be conected to.
Thanks in advance

[gospo]

[muttguru]

Gospo,

that looks like a mechanical fuel pump neaby......is the vehicle an M151A2 ?

ken

[gospo]

Hi, no its A1.Indeed it has a mechanical fuel pump as well as electrical. my fuel safety switch as you can see on the photo before has closed outlet and as I know there shoud be some pipe/hose. Any idea where it should go?

[muttguru]

Hello Gospo...........

The unit is the oil pressure safety switch (OPSS) and the connection on the side of the switch is for a ventilation line. I assume it has been blocked off because the oil pressure safety switch is no longer used on your vehicle. The purpose of the OPSS is to allow the electric fuel pump to send fuel to the carburettor when the oil pressure has not built up sufficiently at startup. The OPSS also turns off the fuel supply if the engine is running when oil pressure drops too low. As you are using the mechanical fuel pump, the OPSS will not be needed.

ken

[gospo]

Thanks Ken for further info.
But first of all it's is in use in my car (i think) , secondly I have electrical pump in the tank.
I'm wondering if the outlet is closed and maybe it is the reason why my vehicle work perfectly 10 minutes and than stops...
I gues that something is wrong with my safety switch, and when oil prssure is high enough as it should be, safety switch should stop the fuel pump.In my case it stops but the fuel doesn't go - after 5 minutes when engine is off, car starts again - so oil pressure change mode again to switch on electric fuel pump.I just orderd new safety switch but problem is that I have no idea where the vetilation pipe from safety switch outlet should go?:(
Do you have any photo or diagram to make conection as it should be?
Another thing is can wrong safety switch couse situation like mine?
Thanks again

[Fil Bonica]

All you need is one fuel pump. Either the in tank electric or the external mechanical.
You may have an entirely different problem with the engine.
Figur out the fuel issue first and then troubleshoot the engine problem.

Fil Bonica

[svramselaar]

hi

as fill mentions you only have to use one pump

for the switch you have three wire`s 77 - 77A - 77B

wire 77 A get + from the contact (from a fuse )
wire 77B get + from the starter as you start
wire 77 go to the pump

the switch as he has no oil pressure connects the wire`s 77B and 77
if you now start the pump gets power from 77B to 77

wen the engine runs ( oil pressure )and you stop starting is went over to wire`s 77A and 77
now gets the pump power from wire 76 (contact ) to wire 77 pump

george

[svramselaar]

hi

sorry at the last line i put 76 it must be 77A at the wire

george

[gospo]

Guys thanks but it was not a question.I need photo or diagram how and where connect pipe from safety switch.....or can it couse symptoms like mine...

[Fil Bonica]

The open line is nothing more than a breather for switch and not sgnificant to vehicle operation.
Plug it if yo want or remove switch completely and plug hole in casting.

Then you can troubleshoot the engne failure.

Possibly ignition or fuel problem.

Fil Bonica

[rickf]

All that pipe is is a vent line that goes up to the carburetor. It will not cause any symptoms of any kind by not being connected. What symptoms are you having? What the others are saying is that if you have the mechanical pump you do not want to have the electric pump running at the same time. It may not hurt anything but if the diaphragm in the mechanical pump gets a leak in it you could be pumping a lot of gas into the engine crankcase with the electric pump. Or into the air cleaner through the fuel pump vent line which is the same line which would go to the oil pressure safety switch if you had a vacuum pump instead of the mechanical fuel pump.

[Mr. Recovery]

Guys thanks but it was not a question.I need photo or diagram how and where connect pipe from safety switch.....or can it couse symptoms like mine...

This is the best photo I have right now, I'll look for more and post them "if" I find any. The line on mine makes a T connection with the distributor vent line.



OK, found another.

[JeepMagician]

The oil pressure switch is connected to small tube that runs to a three way T hat is attached to the air cleaner, that has a tube that goes to the cowl that connects the fuel tank vent and wiper return IIRC.

[JeepMagician]

Look for rubber line going to small Bass color Tube.. Goes to Aircleaner..



Black clothed Tube goes from air cleaner to Cowl where it Tees with Wiper and Fuel vent.