Help?! 80 series - engine not switching off... randoms

[Dave_S]

Hi

Jan called me earlier - said the 80 series was making a weird noise and wouldn't switch off. She messed about with it, the noise stopped and the engine turned off normally. She re-started okay and drove it home, and it hasn't done it since.

My immediate thought is something like a stuck solenoid. But given recent threads about trucks with electrical gremlins going up in flames I am a little paranoid. I'll disconnect the batteries pending more investigation, but any thoughts/suggestions welcome!

Cheers

Dave S

p/s I am really starting to get tired of old XXXXing trucks!!!

 

[Chris]

I'd agree. The only way to stop a diesel if to remove fuel, remove compression, cut off the air or run it into a tree.
I'd say perhaps the fuel cut off wasn't working correctly plus there is a vent to atmos for decompression isn't there to prevent dieseling run-ons?

More than that I can't say.

Ps they're not old XXXXXing trucks; they're classics.

 

[Dave_S]

Aye - my thoughts re diesels Chris. Its the "weird noise" thing thats throwing me a bit - thinking a solenoid buzzing, seems the most obvious answer, but as its running fine now its almost impossible to tell!

 

[Dave_S]

Oh - dumb question - where is the fuel cut off solenoid???

 

[nick_the_fish]

reminds me of my old Austin Meastro when I was 18. We'd turn her off and she'd keep running on for a good 20 or 30 seconds before giving in for the day

 

[Higgy]

Its a long shot but could it be bad/worn contacts in the ignition barrel / worn key. Its just a similar thing happened to me in a Citroen Belingo van... the contacts inside were so worn sometimes the stop contact would be touching the start contact and so on.. only a new barrel and key fixed it... Like I said, A long shot... But I do remember frantically wiggling the key to get it to stop...

 

[chapel gate]

Not heard of it happening on an 80, but recently the unimog would keep running once the ignition had been turned off. After a couple of minutes the engine would stop. a few weeks later turning the key did nothing. It ended up stuck in the start position.

 

[AndycruiserguyLomas]

Sounds to me like the contacts in the starter fusing together.

 

[Dave_S]

Andy - not sure I follow - the truck wouldn't switch off, when running - not sure how the starter contacts would have any bearing on this. Am I missing something?

CG and go - yeah - weird... and as is often the case I can't get it to duplicate the problem now - its starting and stopping normally, no weird noises or anything.

If anyone can point me at the cut off relay, I'll take a look at that - just don't know where the blasted thing is, as the diagram I found on line for this is completely unhelpful!

Cheers guys

 

[AndycruiserguyLomas]

Andy - not sure I follow - the truck wouldn't switch off, when running - not sure how the starter contacts would have any bearing on this. Am I missing something?


Cheers guys

Only that when the starter contacts are stuck together the engine is still turning when you switch off with the key because the starter is still turning the engine. If it comes unstuck there is no guarantee it will do it again when you start it up.

 

[Dave_S]

Hmm - but in that case the starter would have been engaged throughout, which I'm sure Jan would have noticed. Cheers.

 

[AndycruiserguyLomas]

Hmm - but in that case the starter would have been engaged throughout, which I'm sure Jan would have noticed. Cheers.

Ok its just a suggestion, let us know when you diagnose. We can never stop learning.

 

[Dave_S]

Cheers fella!

I do hate random faults - at least when something breaks you can identify what's happening and fix it. Something like this can lurk about....

 

[Knucklehead]

crap pics but might help for fuel cut off on the pump if that is the cut off being asked about...

 

[Dave_S]

Thanks KH - thats what I was trying to identify. Will have another look tomorrow in daylight...

 

[StarCruiser]

I tried posting this earlier, before Andy, but my phone froze. I had the same thought. Depends how mechanically aware Jan is. I get ‘the car’s making a noise’ from mine.

Could the Wierd noise thing be girlie speak for the starter continuing to run? This would point to starter contacts welded in.

Check oil level. If excessively high, through fuel leakage perhaps, it could possibly breathe a bit in.


In any case, intermittent faults are a pig to find. It’ll only do it for Jan of course.

 

[Dave_S]

Jeez - you've not met Janet then?! She's not a mechanic by any means, but she's definitely not a girly girl (she likes big trucks and V8s). I'm pretty confident she'd spot a stuck starter. But thanks for the thought. We'll run it around and see what happens I guess. Cheers for the responses all.

 

[StarCruiser]

Can’t say I have Dave, no.
Sounds like between you you’ll have it sorted.
Good luck with it.

 

[frank rabbets]

The fuel cut off valve on the 24 valve is in the injector pump. You will be able to trace a single core wire from the rear of the pump. That wire connects to the valve and the only way you can turn the fuel supply off is to either turn the ignition off or cut the wire. There is no way to mechanically turn off the fuel by manipulating the valve.

 

[Dave_S]

The fuel cut off valve on the 24 valve is in the injector pump. You will be able to trace a single core wire from the rear of the pump. That wire connects to the valve and the only way you can turn the fuel supply off is to either turn the ignition off or cut the wire. There is no way to mechanically turn off the fuel by manipulating the valve.

Cheers Frank - so is the valve at the pump a solenoid or what? The truck has a hidden security switch to cut off power to the pump, linked into the power feed already, in case we need to shut it down, but I'm trying to pin point the problem too. Is there something in the cut off valve that could be misbehaving??

(Oh - and its behaving itself since the original problem - started and stopped perfectly this morning!).