Cold start problem - L series diesel

I've searched and read another few threads on this, but can't seem to find an answer for my symptoms and coming into the proper cold months I need to get it sorted!

My car has had new glow plugs and a battery, starts quickly first time all day, but takes ages turning first thing in the morning when it's cold. I've tried turning the key to position 1 to light the glow plugs light until it switches off, then backing off and repeating a few times but this doesn't seem to help.

It runs great and nothing's been changed recently that would have otherwise affected it. One clue to the problem source may be in the glow plug light, as the illumination time doesn't change whether the car is hot or cold, so my thoughts were that the sensor that controls how much heat the plugs give is shot? Where is this sensor and what is it called?

I can't think that other problems such as timing, injectors etc could be to blame as I have no other issues, only when the block is totally cold, but maybe someone else can contradict this?

Thanks in advance for your help!

Check for perished leak off hoses,they will pull air in overnight/long idle periods.Unless its very cold or the engine is badly worn the L series shouldnt need much help from glow plugs.

Glow plug duration is dependant on the signal from the ECT sensor, if it fails completely the MIL should come on. Could be working but out of spec I suppose.

TBH I suspect injector pump timing, it's a far more common cause of this issue.

Thanks very much for your input, I really appreciate it!

@ eightinavee - which are the "leak off" hoses? That'll be an easy enough check for me to complete tomorrow if I can find them!

@ chaser - I have no warning lights up, but as you say the ECT sensor could just be on it's way out. Where is this located on the block? Otherwise, can the injector pump timing be altered or is it simply a replacement part that is required to rule out this issue?

The leak off hoses are the small rubber hoses that link across the 4 injectors and back to the top of the injector pump.
A failing coolant temp sensor could be a problem,but as it starts well all day and is only a problem first thing it puts me off that issue.The other point is that if there were a timing issue its most likely the engine warning lamp would come on as the ecu uses the needle lift sensor on one injector to tell it when the start of injection commences.Using this and the crankshaft position sensor it has closed loop knowledge of the injection and if the timing solenoid cannot alter the timing to the optimum position it will log a fault and put the light on.

Excellent - thanks very much for that. I'll give it a good check over now and report back!

Accurate basic fuel injection pump timing can be lost when changing cam and FIP belts (every 48k)

Sure there is an attempt to correct injection timing electronically but basic pump timing has to be correct.

There have been many instances of poor cold starts due to this, all other starts during the day are fine it's just the first cold sart of the day.

Hi mine was similar....except I have TD4 ..... but last year I put in a cheap set of glow plugs..... worked a treat but did not last. I have now changed over to decent NGK ones and it is miles better. I believe on L series the 4th glow plug is nearly impossible to remove...........my guess is that it never has........as the main injector pump has to be removed OMG! Good luck .... make sure all your glow plugs are changed for quality items (not Bripart)....

I have just fitted new silicon leak off hoses. The ones that were on there were really old and although I didn't find any holes it's probably worth 2 quid on some cheapy eBay red hose!

Easy swap and my bay now looks like a Macca F1...!

Will have to wait until tomorrow morning to see if it's fixed it!

since the leak off pipes return fuel to the tank, I wouldn't hold your breath.

Chaser said:

since the leak off pipes return fuel to the tank, I wouldn't hold your breath.

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Yes, via the top of the injector pump.....

eightinavee said:

Yes, via the top of the injector pump.....

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yes t'd into it's outlet to the tank not the supply...

Chaser said:

yes t'd into it's outlet to the tank not the supply...

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Yes, and what you are failing to understand is that diesel is heavier than air - so overnight if the hoses are porus the weight of the diesel pulls air in as the diesel tries to find its way back to the tank - and because the tee is there at the top of the pump that is where the air ends up.And like any other injector pump they wont start an engine whilst pumping air.
It is a common problem,that L series is now old enough for the pipes to be perished and causing the poor starting.Even if its not its good housekeeping to change them.And its also a good place to start as a cheap and easy fix,not relying on paying an indy/garage for a diagnostic session.
Your earlier comment about the ecu fiddling "A little bit" with the timing is way off.If you were to scope it and the crank sensor you would see just how much control it has.(And how it will put the MIL on if the timing cant be adjusted within limits) The electronic control of pump advance is one of the major benefits of the EDC - Electronic Diesel Control,that Bosch worked so hard to get out on the market.Just think how many vehicles worldwide had it fitted - and how reliable it was/is compared to the common rail stuff that followed it.

Chaser said:

Accurate basic fuel injection pump timing can be lost when changing cam and FIP belts (every 48k)

Sure there is an attempt to correct injection timing electronically but basic pump timing has to be correct.

There have been many instances of poor cold starts due to this, all other starts during the day are fine it's just the first cold start of the day.

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We'll just have to disagree over the air in the return line, I'm simply posting my opinion and experience.

As you can see I didn't say the ecu fiddled a little bit, I was acknowledging that there is electronic control over timing but I stand by what I say that basic timing has to be correct. It really does cause poor cold starts on an L series and I've never seen it light the mil, I don't know why, I'll leave that for you to ponder.

Well aside from looking a bit better and ruling out one cause of the problem, the new hose hasn't helped as I discovered this morning! Thanks for the help and advice so far anyway guys.

I chatted to my mate yesterday who suggested a cheeky non return valve as far through the fuel system as we could easily install, to see if that would stop any air ingress getting near the injectors when left overnight. Obviously it wouldn't actually "fix" the original cause of the problem, but may at least show which side of the valve the leak was!

Any other thoughts...?

Well thats a shame,but still its ruled it out so we need to look further.Is there any smoke from it while its cranking before it starts ? All I'm getting at is to determine if its injecting any fuel or not.
It would be good to see what the engine ecu is seeing from cold too - via Testbook.You say it has a new battery but how fast does it crank when cold.If the alternator is not brimming off the battery the cranking speed may be low enough for it not to want to go.Have all the battery leads and earths been checked for tightness or corrosion.Reason I say this is just as an example my wife uncle has an 850 turbo Volvo that used to play up with starting when the temp dropped below about 4c overnight - but would be fine all day.The local garage gave up on it after checking the battery, alternator and starter.So did 2 Volvo garages too.But the car would start instantly given a quick push..... I had a good look around it and found an earth strap disconnected down under the bell housing which I refitted - its been perfect ever since.
So,has the problem come on slowly,or been since work has been done/something changed ?

It's been getting worse over the past couple of months, no work has been carried out that would have changed anything starting related...

There is a small amount of smoke emitted as it's cranking, then a healthy puff once it's running! It can then be switched straight off and started on the button however.

My previous Golf had starting woes too and I reckon removing and cleaning the battery wires and earth straps around the bay and cleaning up the stater motor fixed that, although it struggled when hot too.

I will have a proper check of all the wiring tomorrow, although I'm sure this problem would cause symptoms when hot too?

No,they turn alot easier when warm,it could just be that.I had a 900 Ducati MHR that ran straight 40 oil,when it was cold the only way I could kickstart it was by warming the engine with a space heater !

can you loosen one injector pipe prior to first start, if it bubbles you will know air is present, if fuel emerges it is another theory put to bed, it could also be a bad injector seat allowing compression gasses into the fuel pipes.

I'll have 1 last attempt to convince you (and eightinavee) that it can and just might be timing.

The timing device needs hydraulic pressure to advance the timing, if static timing is out, during that initial cold start it struggles to create sufficient adjustment.

If you have a manual and the skills it won't cost you anything to check the camshaft and injection pump timing, if it's not that then there's nothing lost but your free time.

Here's a link to 2 cases in the same thread, it's a bit protracted but symptoms and cure are the same.
freelander l-series engine starting problem??