Early Warning of starting issue 1.6HDI?

[Robho]

Mine has always started first turn of the key – albeit when cold, rather lumpily.
 
At the weekend it turned over for a bit and sounded as if it was going to catch but didn’t. Took a couple of attempts. Same this morning and it took three tries.
 
Once started it drove normally, nothing unusual.

(and after my 5 mile journey, then unused for about half an hour, it started first turn (and same again when tried after standing for half hour once home). Obviously both the latter were with a still-warm engine.

Just wondering if this behaviour might point to anything I could look at hopefully before it worsens? (Fyi, battery is fit, as is starter motor - replaced a couple of months ago).

Let me know if any more info would help?

Many thanks.

[Sol]

If the cranking speed is correct (good battery etc) then this behavior is usually down to air getting into the fuel lines and draining them back to the tank. (or you have a small leak) - try putting the ignition on for 6 seconds at a time, three times. before trying to start it fully the next morning.

If it then starts instantly once the lift pump has had 3 shots to prime the system, then I'd suspect you have air getting in somewhere, likely into the tank return line or filter housing.

My last M59 used to be horrible for the frist 30 secs, lumpy smoky hunting idle, then after that, smooth as butter. I pinned that one down to the EGR sticking and mostly fixed it with an EGR blank plate.

But it always did start. An Audi I had, did what your HDi is doing, and it was a leaking seal on the main injection pump return, letting air in and draining the system back to the tank.

[Robho]

That's great feedback, thanks. Will try as suggested.

[Buki]

I had an M59 1.6HDI, there was no lift pump in the tank...
Instead of this, there was a hand priming pump above the engine, left side of the fuel filter. If you have this design, try pumping with the pump until it becomes hard, before starting.

[Sol]

Good point Buki, if the priming bulb is fitted, there's no lift pump.

[Robho]

Good point Buki, if the priming bulb is fitted, there's no lift pump.

Morning

Just as Zion suggested - tried the 3x switch on before attempting to start - and it started immediately as I turned the key. Spot on. 

I'm afraid diesels are a bit of a 'black art' for me... any tips on where to start looking for a suspected leak would be great, pls. 

Don't think I've noticed a priming bulb - would the technicque above mean mine wouldnt have that, anyway?

I'm interested in the EGR blanking - but there's so much rubbish on eBay, can you direct me to a decent part pls?

thanks again.

PS
It is of course only a 'sample of one', but after the 3x switch on, as described, on start up there was no blue smoke. Is this just a fluke, or might it be connected with the fault?

[Sol]

I think it means you do have a lift pump and it primed properly before starting. The priming bulb is on top of the engine and is noticeable although slightly recessed and not possible to "grab" but more press with the thumb. I think the test probably proves you have a lift pump and that the system is draining back overnight.

Could be a cracked rubber leak-back pipe between injectors, or a loose fuel filter lid, crack in the fuel filter casing, worn fuel union somewhere between the engine and the tank return, it may be hard to pin down.

No smell of diesel at the engine or wet areas? Some ingress of air results in no leak of fuel but lets air in and so the fuel runs back to the tank.

Something else I've seen is people overfilling the tank so it spurts out, then fuel runs down the air vent at the filler neck (small hole / tube that lets air in as fuel is drawn out) and the fuel soaks and destroys a little cotton wad filter in that tube, causing a slight vacuum in the tank while running...then overnight, that vacuum sucks the fuel back down the lines to the tank.

[Robho]

I think it means you do have a lift pump and it primed properly before starting. The priming bulb is on top of the engine and is noticeable although slightly recessed and not possible to "grab" but more press with the thumb. I think the test probably proves you have a lift pump and that the system is draining back overnight.

Could be a cracked rubber leak-back pipe between injectors,  or a loose fuel filter lid, crack in the fuel filter casing, worn fuel union somewhere between the engine and the tank return, it may be hard to pin down.

No smell of diesel at the engine or wet areas? Some ingress of air results in no leak of fuel but lets air in and so the fuel runs back to the tank.

Something else I've seen is people overfilling the tank so it spurts out, then fuel runs down the air vent at the filler neck (small hole / tube that lets air in as fuel is drawn out) and the fuel soaks and destroys a little cotton wad filter in that tube, causing a slight vacuum in the tank while running...then overnight, that vacuum sucks the fuel back down the lines to the tank.

Thanks. 

No noticeable smell of diesel / wet areas. At the weekend, I'll make a search in the areas you suggest. I've had the vehicle 3 years and as a starting point did a thorough service when I got. I thought I had changed the fuel filter, but searching back through the history this morning, the invoice shows it was out of stock at the time, and I cant find anything to say it was delivered later (and can't remember!). Worth changing as a precaution, would you say?

(and would appreciate guidance on the EGR blanking kit as bove pls).

thanks again.

[Sol]

It may be worth changing out indeed. Just make sure to fill it with fuel before starting up again.

On the EGR blank, the 8v one (later engine) is this one:

https://www.ebay.co.uk/itm/113128797031?...R46utODdYA

You just slacken the two bolts on the EGR valve to alloy flange connection (near the fuel filter area) and slip the steel plate in, then tighten up. No need to fully remove, but from memory I had to unplug and remove my fuel filter housing to get access so worth doing both things at the same time.

After the blank is fitted, you won't get an engine fault light but it will always have a stored code for "airflow - value incorrect / not as commanded" or something like that. But it will not do any harm, just to make you aware for a future code scan, ignore that error.

Post only the first 8 characters of your VIN (or PM the whole VIN to me) and I'll check exactly which engine you have so you get the right blanking plate.

[Robho]

PM sent, thx.