CDTi Not starting

[vilas66]

So my donor cdti doesn't want to start anymore. I want to keep her running although is a donor car.
It's a facelift single low pressure pump and the flow is excellent.
What I've tested since now:
- camshaft sensor disconnected and reconnected: the rev counter needle moves when cranking
- disconnected maf - no joy
-disconnected rail pressure sensor - no joy
- the ECU is and has always been dry and shiny
For obvious reasons (it's a donor car) I can't get a T4 session but I had a chance to use Toaf and attached live results of the TOAF session.
Before I go any further, can be the HP fuel pressure regulator the culprit of a a very low rail pressure as discovered by Toaf ?
Values are while cranking
Any help or idea appreciated.
THX

[Yorkshire GOC]

Under bonnet fuel pump playing up/failed ? Happens especially when the tank is less than half full it can cause non starts.

[Yorkshire GOC]

Also may be worth doing an injector leak back test .

[vilas66]

Originally Posted by Yorkshire GOC

Under bonnet fuel pump playing up/failed ? Happens especially when the tank is less than half full it can cause non starts.

No under bonnet fuel pump: it's a Facelift car with a single pump configuration.
Also the low pressure, is great :-)

[Arctic]

Hi Canio.
Try removing the low pressure fuel connector on top the fuel filter and see if it starts, before re-instating it clean the contacts with some electric contact cleaner, also the pressure rail plug spray that with some contact cleaner.

When was it last started and did it fire up right away?

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If the above does not help try a sniff of engine start in the EGR

[vilas66]

Originally Posted by Arctic

Hi Canio.
Try removing the low pressure fuel connector on top the fuel filter and see if it starts, before re-instating it clean the contacts with some electric contact cleaner, also the pressure rail plug spray that with some contact cleaner.

When was it last started and did it fire up right away?

If the above does not help try a sniff of engine start in the EGR

Low pressure test already Done ! No joy Artic and... yes ! last time she started she fired up strait away and after a few months !

[Arctic]

Did you try it with easy start ? into the EGR just a sniff while someone cranks the car over, also try a leak back test on the injectors, if no joy then check the regulator O-rings.

Is the battery on the car fully charged ? you can't even rule out the battery. This is true especially if the ECU capacitors are not cranking at their correct voltage.

[ADO282]

Injector leakback perhaps?


If you look at the figures of the live data in your screenshot, the rail pressure is 3000kpa and the stated required pressure is 30000kpa.


So it would appear your car has more than sufficient low pressure to start, but insufficient high pressure.



I found out with my friend's car which had a badly leaking injector a couple of weeks ago, when we viewed the high pressure figure, it slowly rose as the car was cranked, and the car fired when the figure reached 12000kpa, this took around 20 seconds of continuous cranking.


It could be started with easy start or brake cleaner, or indeed any aerosol spray with a flammable propellant.


As I understand it, the high pressure pump on the diesel is driven by the camshaft chain, so it will be running at half engine speed, so with a leaking injector it won't be able to supply enough diesel to allow the injectors to open at normal cranking speeds.


Does TOAF show any errors for the engine management??

[COLVERT]

As Arctic says in his post above try it with some easy start.

This will spin the engine up fast enough to overcome any slight pressure loses here and there.



Ps. If you are simply wanting to store your engine then starting it up now and then can do more harm than good. Unless you run it long enough to get it really hot you will be generation corrosive elements inside the engine.----


Engines stored in a sensible place can just be left alone and won't degenerate.-----

( Killed by kindness springs to mind.--- )

[Mike Noc]

Originally Posted by vilas66

What I've tested since now:
- camshaft sensor disconnected and reconnected: the rev counter needle moves when cranking

If the rev counter needle moves then that shows the crank sensor is working - I don't use TOAF but that should be able to flag up a faulty cam sensor.

Originally Posted by vilas66

Before I go any further, can be the HP fuel pressure regulator the culprit of a a very low rail pressure as discovered by Toaf ?
Values are while cranking
Any help or idea appreciated.
THX

Yes, as ADO282 said could be due to a badly leaking injector, or maybe a faulty fuel pressure regulator or wiring to it?

Originally Posted by ADO282

As I understand it, the high pressure pump on the diesel is driven by the camshaft chain, so it will be running at half engine speed, so with a leaking injector it won't be able to supply enough diesel to allow the injectors to open at normal cranking speeds.

Driven from the first cam chain Chris, so runs at 3/4 engine speed, and the other quarter is reduced on the second chain to allow the camshafts to run at half engine speed.