2004 Mercedes MB140D glow plugs

jasongroves, May 30, 7:46am
2.9L 5 cylinder diesel.
Issues with rough starting and the lack of the glow plug light coming on Inconsistent, sometimes comes on while driving along, accompanied by the van running rough).
Today I tested the resistance at the relay/timer connection plug and got consistent readings of 1.6Ohms at plugs 2-5 but showing an open circuit on number 1.
I'm guessing this would be a good clue that glow plug number one is rooted!
If so, in what order are the glow plugs located!
Is plug 1 closest to the front of the vehicle! Or the rear! (I'm really hoping its the rear as its MUCH easier to access.lol).
Anyone familiar with these vans/engines!
Cheers all.

carmedic, May 30, 9:38am
# 1 is closest to the front sorry!

jasongroves, May 30, 9:57am
Bugger.I had a feeling it was:(
Looks like the radiator has to come out!

jasongroves, May 31, 5:15am
Actually wasn't too bad and could be accessed through the interior using a long enough extension.
Repco had plenty in stock so shot down and got one and changed them over.
Hey presto, light is back on and functioning as it should and starting is MUCH better.
Replaced a few perished vacuum hoses etc while I was at it too:)

intrade, May 31, 8:33am
2004 commonrail i would guess they are based on the mercsprinter engine i think the later blocks.

jasongroves, Jun 3, 11:19am
Yep its common rail.
For some strange reason it has started running on when you turn the ignition off.
When you turn the ignition off the revs drop to around 200rpm and it just keeps running. You have to stall it in high gear to get the engine to stop.which isn't ideal:)
Can anyone think of a reason for this!
It only started doing it over the weekend and had done 300-400km of perfect running since the new plug and filter etc was installed.

stevo2, Jun 3, 6:09pm
Yes its called a "runaway diesel" http://en.wikipedia.org/wiki/Diesel_engine_runaway Google it for more info. I've had it happen in my old Diahatsu truck where its revved to the redline for 10 seconds then died. Also seen it in a late model Pug that revved its tits off then blew.

carmedic, Jun 3, 9:09pm
Doesn??

jasongroves, Jun 4, 8:49am
Thanks guys.
Will have a look tomorrow and post back once Ive got a rough idea of whats going on:)

jasongroves, Jun 8, 2:58am
Finally got a chance to look at it today.
All vacuum hoses etc are where they should be and in good shape.
All glow plugs are connected correctly (nothing is loose).
Brake lights are working fine and made no difference when I removed them sadly.
Could it be a fault with the ignition itself perhaps!
Im fairly stumped to be honest.

jasongroves, Jun 8, 2:59am
Nothing like that (thank God). Thanks though.

carmedic, Jun 8, 4:51am
I think that??

jasongroves, Jun 8, 11:19am
How would I go about testing! Or anything else I can rule out!
Thanks for all your help.

carmedic, Jun 8, 9:48pm
Start by unplugging the ignition switch after you switch it off and it??

supernova2, Jun 9, 9:34am
I'm just guessing but I would think there is a stop solinoid somewhere in the fuel system, maybe you have knocked a wire off or broken it etc.Test light should be all you need to find if its getting power.

jasongroves, Jun 9, 11:52pm
Bugger, hope its easy to find if that's the case:)
Strange that it was running perfectly and turning off as it should for several hours before this issue came up.
Would be a lot easier if there was room to see and move under the engine cover.lol.

jasongroves, Jun 13, 12:14am
Cant find any broken or disconnected wires, which is a shame because that would have been a relatively easy fix:)
On further research it turns out this version of the Mercedes OM602 is NOT common rail, the Sprinter variants were but not the Ssangyong ones.
Apologies for that, the van belongs to a friend an I am more familiar with petrol donks:)
From wiki:
'On many OM602 engines fuel injection is indirect. A Bosch PES in-line injection pump is used, with a mechanical governor and vacuum-operated stop control.'
The engine is starting and running beautifully.just not turning off:(
Can anyone direct me to where the 'vacuum-operated stop control' would be located!
Thanks all.

chazboner, Jun 13, 8:28am
Hi jason I have one of these had the same problem its a vacume problem I found a broken t conecter and replaced all fixed

jasongroves, Jun 13, 9:00am
Great, thanks for that.
Will look into that as soon as the weather allows:)

carmedic, Jun 13, 8:47pm
I was surprised when you said it was common rail!
The vacuum shutoff is on the top of the injector pump put a hose on it and suck (with mouth if necessary!) with the engine running, is it stops you have a vacuum leak elsewhere if it won??

jasongroves, Jun 14, 12:52am
Cheers 'medic.Ive never sucked off a Merc before;)
Will get onto it and hopefully find the problem.and hopefully its an easy enough fix.

next-to-normal, Jun 15, 6:31am
check the vac hose near the front of the motor too, also your shut off valve is located in the middle of you inlet manifold, look for a lever at the bottom