208d 1996 wont stop running- newbie :)

[allan.p]

Hi guys
I have recently purchased an old 208D van for work and the starter motor died on me, so I replaced the start motor and it now fires up better than before but it wont switch off - I can take the key out of the ignition and it carries on with all the dials working etc . If I put the hazard lights on then the guages drop as the lights flass so I am assuming thats cos it's drawing power from the alternator etc.
So my question is - is this caused by a vacuum issue which I have seen some other references to or is it something like an ignition solenoid ??
if its the vacuum then does anyone have any idea why replacing the start motor may have caused it and are there any drawings etc for where the pipes go ?

I'm very grateful for any assistance

Thanks

Allan.

 

[simon_wall69]

You could have knocked one of the vacuum lines out when replacing the starter motor - it is very easy to do.

 

[allan.p]

cheers

Thanks for the reply - but I took the start motor out through the bottom and I cant see any vacuum pipes around that area.
If I had a leak would it not result in any other failures ?

The only thing I can think of is the pipes near the ignition switch - there are two there - how can i prove if they are ok ? if i disconnect them should I be able to test the system in some way ?

I know this probably sounds very basic but I have never worked on a diesel before never mind a merc van :lol:

Thanks again

 

[wireman]

The vacuum system stops the engine by applying vac to a capsule on top of the fuel pump. The vac comes via a valve on the ign/steering lock from the engines vac pump.
In the run position the valve opens the pipe from the pump to air, closing off the vac from the engine. In stop the valve applies engine vac to the pump closing off the air vent.

In run there should be about 20" of mercury vac at the valve, and nothing at the engine.
In stop there should be about 20" at the pump which should remain there for some time after the engine has stopped.

The rubber joint pieces on the vac lines can degrade and break off or split and leak.
It is not unknown that the vac capsule on the pump fails. The emergency stop lever on the fuel pump should stay pulled down (it moves down when you stop the engine), if it barely moves down or comes back up once the motor is stopped you have a leak - somewhere.

Most of the vacuum systems on your vehicle will be from seperate tappings and restrictors off the vac pump and so a fault on one system will barely affect any other vac components.

 

[allan.p]

Ok thanks for all your help

I took out the vacuum "switch" from the top of the ignition and when its in the stop position I can hear air being sucked which indicates a leak ?? so if I take off the pipes and connect them together it stops the engine - so does this mean the "switch" is faulty ??

Sorry for being daft but I have never worked on an engine like this before :Oops:

Thanks
Allan.

 

[wireman]

Yes, if you wish to verify it by connecting a vac gauge to the fuel pump side of the "switch" it should read a vacuum when you turn the switch to off.

A similar fault occurs if the pipes are crossed over at the switch.