XUD run-on

[minimad5]

Hello everyone,

Wondering if any XUD experts can help me out here.
The past few days my TXD Turbo BX has been "running on" for a second or two, after turning the ignition off.
Yesterday however it decided to run continuously, even with the key out of the ignition.
So i thought the problem must be the Diesel Stop Solenoid, so today i replaced that and still the problem persists.
I have resorted to stalling it in 5th in order to turn the engine off, which is not ideal and i fear may damage other components.

So if anyone could advise me to what could be causing the engine to run with the ignition off, that would be fantastic.

Thank you.

[mat_fenwick]

Did you check there was nothing under the solenoid plunger when you renewed it? Such as a little crumb of rubber preventing the plunger seating...

Also check whether the solenoid has 12 V across it with the key off - obviously it shouldn't.

[minimad5]

Thanks for the quick reply !
Yes checked both of the above:

12v+ when running (with key in ignition)
0V when still running (with key out of ignition)

[Mothman]

The engine wasnt starting to race was it? If it did its possible you are running on engine oil getting past the piston rings, usually a sign of a very worn engine and if allowed to continue will ruin the engine in a spectacular way.

Andy

[Oilyspanner]

Can you hear the stop solenoid operating ? they usually make a pretty good click, I would be looking in the port to see if there is anything remaining from the old solenoid too, a fragment of rubber, I think there is a stop lever on the pump too depending on model.

[minimad5]

The engines RPM do not increase, which is why i did not mention the engine running away.
I will try grab a short video of what happens later or tomorrow, but the only way of describing it, is it is like you have not removed the key at all (So it is just idling normally) but with the battery light illuminated.
Note that the battery light does not illuminate when the car is idling with the ignition on and key in.

It has had the ignition switch changed by a previous owner, but since no voltage is getting to the solenoid when the ignition is off, i don't think this is the problem.

Mr Oily:
Yes the stop solenoid can be heared (even tested it with the use of some spare wire) , even if the solenoid did not "work" surely all this would do is not create a magnetic field, thus not pulling the plunger up = Blocked hole and would not Run at all ?
Where my problem is the opposite.

[BX Bandit]

Mr Oily:
Yes the stop solenoid can be heared (even tested it with the use of some spare wire) , even if the solenoid did not "work" surely all this would do is not create a magnetic field, thus not pulling the plunger up = Blocked hole and would not Run at all ?
Where my problem is the opposite.

But if, as others have suggested, there is a piece of rubber (or some crap preventing the solenoid seal from correctly bedding) then this would display the symptoms you have!

DO use the stop lever on the pump rather than stall it as Oily alluded to, all pumps will have a stop lever.

I believe there is a spring the other side of the plunger to make a good seal to cut the fuel off, is the spring there? They are easily lost if your plunger fell out!

[MULLEY]

If you don't use the stop lever, you could shatter the clutch

[Thread Bear]

I assume the drain back for unused fuel to the tank has a one way valve. If not what stops it from syphoning back as the system is hydraulicly complete, isn't it? You see where I am going.

[minimad5]

But if, as others have suggested, there is a piece of rubber (or some crap preventing the solenoid seal from correctly bedding) then this would display the symptoms you have!

DO use the stop lever on the pump rather than stall it as Oily alluded to, all pumps will have a stop lever.

I believe there is a spring the other side of the plunger to make a good seal to cut the fuel off, is the spring there? They are easily lost if your plunger fell out!

I removed the stop solenoid again today, just to double check everything and can say that there is no foreign body or 'crap' preventing a good seal.
All seems to work correctly with the solenoid (bench tested), though the spring does look a little short, so swapped it out for the old one, and it is in exactly the same depth / place, anyway put it all back together and still the same problem.

So ignoring the problem for a wee while i took a trip out to pick up a mates stainless exhaust, queue a sudden loss in power and absolute no boost from the turbo at all .... I think (do correct me if i am wrong) but the turbo seals are weeping, allowing the car to run-on slightly from the oil, thus starving the bearings and leading to seized / FAWKED turbo and no boost.

I could however be totally wrong, so i shall pull the intercooler and so on off tomorrow and see what the deal is.
I would imagine if it were running on oil, that it would not run as smooth as it does also noting that the oil level has not dropped since i last checked it (This being monday)

Thank you all for your suggestions and comments.

Where would i find this "stop" lever ?

[minimad5]

I assume the drain back for unused fuel to the tank has a one way valve. If not what stops it from syphoning back as the system is hydraulicly complete, isn't it? You see where I am going.

Honestly - i don't know, when it comes to XUDs or any diesels for that matter, i'm not that good

[MULLEY]

The stop lever is on the diesel pump.

[BX Bandit]

The pressure within the pump AND gravity stop the fuel draining back and it's not hydraulically complete as there is a breather on the tank.

The Bosch stop lever is mounted on the front of the pump, the Lucas I think is on the top but located towards the back left hand side.

What mileage has the car done? Any wierd noises during boost? Do you have a kkk or garrett turbo?

[Oilyspanner]

If your turbo seals are failing it will drink the entire contents of the sump in short order, you would also be laying a smoke trail of awesome proportions, you will find an oily mess in the intercooler, they all do that sir, what about the on boost fuelling pipework between intercooler and pump ?

[BX Bandit]

/\ good call, hadn't thought of that!