Diesel Taking a Long Time to Start and Cuts Out
 

Hi all,

Need some help with my 75 CDTi 2.0 manual please. It is a 54 plate facelift model.

The symptoms are that it takes a lot more cranking to start than I would expect. When starting, it will take 7-15 second of cranking before it fires up. Generally closer to 7 seconds if I have my foot all the way down to the floor whilst cranking.
Sometimes it will try to fire after a couple of seconds, fail to do so and then continue cranking.

The car will then idle fine for a period of time, but will suddenly cut out with no warning. There is no pattern to the length of time this will take.

Whilst driving, the car has plenty of power and is smooth. Occasionally it will "hiccup" for a second and then carry on.
If travelling slowly in a high gear, (so, say under 1500rpm) it will cut out and take up to 15 seconds of cranking to start again.
There is no noticeable smoke when running or accelerating.

This happens whether it the car is hot or cold.
Leaving the ignition on for 30 seconds before cranking makes no difference.
The battery is good and it cranks strongly.
The plenums are bone dry. No evidence of the ECU having a bath.

The camshaft and crank position sensors have been replaced with new ones. I have removed and cleaned both the EGR valve and inlet manifold - neither were particularly caked up. I tested that the EGR was working with a vac pump and it opens fine with a vacuum applied.

I have changed the PCV filter, as well as the air filter and oil and oil filter (not that I expected that to do anything).

I did an injector leakoff test. After 2 mins of cold running, I had the following:
Cylinder 1 - 12ml
Cylinder 2 - 13ml
Cylinder 3 - 8ml
Cylinder 4 - 13ml
(this included draining what was in the tubes into the catch bottles)

From what I have read, anything under 20ml for 2mins of running is good? Bit concerned why cylinder 3 is a lot lower than the others?

What next? I have run out of ideas? All help and advice appreciated.

I don't know what the problem is but why have your foot on the throttle, I presume that where your foot is?

macafee2

No reason, other than to try it and see if it made any difference. Will do some less subjective tests to see if it does in fact make a difference.

You have a poor electrical contact somewhere. Unplugging and plugging back in the connectors to the various sensors might help. HP pump. diesel filter etc. As you've changed the cam and crank sensors it's unlikely to be either of them.


Holding the throttle down will not help nor will waiting 30 seconds with the ignition on.--After 30 seconds the fuel pumps might well have turned themselves off. They are programmed to do this.

You might find it useful to have read through the ---How-To's--for threads discussing the same problems that you are experiencing.---;)

Be worth checking fuel pressures when cranking, could be a perished O ring on the HPFP regulator.

[QUOTE=TriumphStag;2848410]Hi all,

Need some help with my 75 CDTi 2.0 manual please. It is a 54 plate facelift model.


It could be as said above regarding an O ring failure on the pressure regulator. Personally I think it is a combination of that when the car is running and the Glow Plug Relay when starting as they are known to burn out and would explain the slow starting.
It could also be a simple case that the glow plugs are worn out and so taking longer than they should to heat up. This can be checked by turning the key to position 2 for till the glow plug light goes out, turn it back to off and then repeat twice. On the 3rd time try starting the car. If it starts almost straight away you have your answer as to it been worn glow plugs.

Thanks all,

Will have the next round of trying to fix it at the weekend - am WFH at the moment and it is cold and dark when I have finished work each day :-) plus with WFH I don't need to drive too much :-)

Stupid question - where is the HPFP regulator?

HI Mark.
Not stupid question you either know where something is or you don't many members do not.

The Regulator is on the back of the high pressure fuel pump, with the bonnet open and looking into the engine it is on the left hand side, below and backwards of the alternator below the oil filter, photo below.

https://i.imgur.com/GfortWLl.jpg1

https://i.imgur.com/1tkRUy6l.jpg2

https://i.imgur.com/SH6Jm64l.jpg3

To remove the regulator comfortably it's best to first remove the starter motor, once the regulator as been removed you will need an O-ring kit here below.

https://i.imgur.com/hNMBxx6l.jpg4

https://www.ebay.co.uk/itm/BMW-530d-...1/333540124490

I doubt it's the glow plugs as we don't really need them here in the UK, first you really need to find what the cause is, do you have an under bonnet pump?

[QUOTE=MacRob;2848932]Just tried the test on the glowplugs. Made no difference.

Also - the slow starting is the same whether the car is cold or hot.

Thanks, I have the thing shown in the picture. Is that the HP pump? I thought they were mounted on the bulkhead behind the fuel filter housing?