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Help,418 diesel engine wont turn off

4K views 12 replies 6 participants last post by  jaybkay 
#1 ·
My 93 418 SLD (non turbo) doesn't shut down when I switch it off.I have to stall it to kill the engine.If I do this too many times it's the clutch that will be killed !!

I noticed earlier in the week it would run on very slightly when switched off,this running on got progressively worse until now it doesn't shut down at all.

Is there a solenoid that needs repairing or replacing,if so where-abouts is it ? Is there a site where I can get an exploded view of the part ?

Any thoughts.Cheers John.
 
G
#3 ·
There is a shutdown solenoid on the injector pump - if this is sticking then it may be causing the problem. It will have a single wire on it. There is a little plunger inside which SHOULD shut off the fuel when power is taken off the wire (by shutting off the key). If you remove the solenoid and clean up the plunger that may clear the problem.

I think the power supply to the solenoid is OK because without this solenoid being energised, the engine won´t start.

For the record, there ought to be a "STOP" lever on top of the injector pump - operating this will kill the fuel supply and shut down the engine. Much kinder than stalling it!

It's a Peugeot/Citroen XUD unit so if you can't find a suitable rover Haynes manual, the Pug/Cit ones will do just as well.
 
#8 · (Edited)
Not questioning 2 blokes who know their stuff, but how does the diesel ignition work that's different to a petrol as I know sod all about diesel and would never buy one in a million years?
Doesn't the ignition shut down more than just the fuel pump? As far as I know on a petrol - fuel pump, injectors and main relay would shut off.
Wouldn't the glow plugs shut off with the ignition off?

EDIT: sorry I mean injectors not glow plugs.
 
G
#9 ·
The glowpugs are only on for about 7 seconds during start so they are already shut down.

There is no ignition system at all, so the term "ignition" is misleading.

The fuel injection pump and injectors on this engine are purely mechanical - the fuel is injected as a high pressure spray which is then ignited by the heat generated when the air/fuel mixture is compressed by the piston to a pressure about 23 times atmospheric pressure (petrol engine have a much lower 10 to 1 or so compression rating).

Switching off the "ignition" cuts the power to the fuel cutoff solenoid and as this is designed as a failsafe, the fuel supply to the injector pump is cut and with no fuel to power it, the engine stop. I suspect that sprog's solenoid is sticking open and therefore not shutting down the fuel.

On a petrol car, killing the ignition cuts both the electronically operated fuel injectors and the ignition system.
 
#10 ·
Ah I see, unfortunately you must have been posting while I was changing my post. I was trying to change my post quick cuz I'd made an error and without realising I put glow plugs instead of injectors which is why I just put an EDIT note so as not to confuse the issue.

Thanks for the explanation though Richard. I'm a little more knowledgable on diesels after that...still wouldn't buy one in a million years though.
 
#11 ·
Ashy,diesels are fantastic.I can go 15 miles further up the road for every gallon than a petrol 420.

That's more than 100 miles for eack tank full.

O.K. it's not the quickest car in the world but if I want a speed thrill,I kickstart my Yamaha powervalve and squirt it down the nearest unrestricted A- road.

Being a tight-wad it suits me fine.I will take a look at the fuel solenoid.Here goes another oily hand scenario.

Rovers Rock.
 
#12 ·
ashy said:
Not questioning 2 blokes who know their stuff, but how does the diesel ignition work that's different to a petrol as I know sod all about diesel and would never buy one in a million years?
Doesn't the ignition shut down more than just the fuel pump? As far as I know on a petrol - fuel pump, injectors and main relay would shut off.
Wouldn't the glow plugs shut off with the ignition off?

EDIT: sorry I mean injectors not glow plugs.
I learnt the hard way at the age of twelve,I wandered upon a hymac and played with it a while in field and then couldn't turn it off-40+mins trying in deperation to suffocate the intake, pull off the battery ect... then discovered you only had to pull the throttle all the way back to the stop to cut off the fuel Doh!! thickie, my excuse was my youth.I did dig a REALLY big hole with it what great fun for a kid he he..
 
#13 ·
I had exactly the same problem a couple of years ago. Basically there is a rubber cap in the fuel solenoid (like a tyre valve cover) that covers a hole up when you turn the ignition off. When the rubber fails it doesn't shut the hole off hence the engine carries on. As a new solenoid is about £100 in NZ I carefully made a new rubber cap by using a small piece from a Triumph Herald fuel filler grommet, it's still working.
 
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