Cold starting issue

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Wag
1.8 16v
Posts: 77
Joined: Sat Apr 14, 2018 5:04 pm

Cold starting issue

Post by Wag »

Now its sub zero outside, the old 2.0 hdi has a bit of trouble getting going in the morning.
Recent new battery but really slow turnover first thing.
Pre heater light goes out after a couple of seconds and I try to fire it up. It just about gets going but after that initial fire up its fine all day. I'm doing 100 miles a day so it's getting a good charge time.
Any suggestions?
I thought something might be turning on in the car when I'm not there, as I've previously found the radio had switched itself on before now.
PeterN
3.0 24v
Posts: 1673
Joined: Sun Mar 04, 2012 6:04 pm
Location: Charmouth, Dorset

Re: Cold starting issue

Post by PeterN »

Could be a tired starter motor or a high resistance in the wiring from the battery. Check the voltage actually on the starter when its turning over and then check across the battery as its turning, if there is a large difference check all the connections. Also test the voltage between the battery negative connection and a good earth point, much of a voltage difference would indicate a poor earth connection.

Peter
Wag
1.8 16v
Posts: 77
Joined: Sat Apr 14, 2018 5:04 pm

Re: Cold starting issue

Post by Wag »

Thanks for that. The strange thing is, it spins up freely once it's been started for the day. Does that suggest anything else?
PeterN
3.0 24v
Posts: 1673
Joined: Sun Mar 04, 2012 6:04 pm
Location: Charmouth, Dorset

Re: Cold starting issue

Post by PeterN »

The resistance to it turning is much less when the engine is warm so it doesn't need so much energy to turn it.

Peter
MarkD
Newbie
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Joined: Mon Jan 25, 2021 12:33 pm

Re: Cold starting issue

Post by MarkD »

I have the same issue. If the temperature drops to freezing overnight forget it! Similarly in the summer when it’s hot it’s difficult to start, shudders like mad.
Looking at an earlier post best explanation I’ve seen is that the ecu isn’t getting the correct temperature signal and hence doesn’t open the injectors correctly?
It runs perfectly otherwise, no fault codes, so all a bit of a mastery?
2004, 406 110hdi.
PeterN
3.0 24v
Posts: 1673
Joined: Sun Mar 04, 2012 6:04 pm
Location: Charmouth, Dorset

Re: Cold starting issue

Post by PeterN »

The only other likely problem is air getting into the fuel line, but that would likely make it difficult to start when hot as well, except that when the engine is turning over fast it can pump the air through the system before it gets into the pump and injectors. I have had this problem with my C5. Have you changed your fuel filter lately?

Peter
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Doggy
Mod with a 2.2 HDi, De-Fapped!
Posts: 10710
Joined: Mon Oct 13, 2008 11:49 pm
Location: Northants

Re: Cold starting issue

Post by Doggy »

The ecu will not initiate injection until it 'sees' a cranking speed of >60 rpm

Uneven running immediately after starting could indicate a glow plug problem - the glow plugs continue to operate for half a minute or so after starting to help even things out, (roughness is likely caused by not all cylinders firing initially). I accept this doesn't explain hot starting issues.

Excessive injector wear can also prevent starting, might be worth trying a leak off test.
2002 HDi 2.2 Exec Estate, (2008-12) (wonderful)
2003 HDi 2.2 6-speed Exec Estate (2012-19) (also a gem)
2009 Citroen C5 2.0 HDi VTR+ Estate (godawful heap)
2008 BMW E91 330i touring (great fun - murdered by a reversing SUV)
2007 BMW E91 325i touring (slower smoother quieter)
MarkD
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Joined: Mon Jan 25, 2021 12:33 pm

Re: Cold starting issue

Post by MarkD »

PeterN wrote: Tue Jan 26, 2021 11:30 am The only other likely problem is air getting into the fuel line, but that would likely make it difficult to start when hot as well, except that when the engine is turning over fast it can pump the air through the system before it gets into the pump and injectors. I have had this problem with my C5. Have you changed your fuel filter lately?

Peter
That’s very plausible. I have changed the fuel filter, it made no difference, although the pipe in did come off, so maybe there’s a weak point in the system?
MarkD
Newbie
Posts: 6
Joined: Mon Jan 25, 2021 12:33 pm

Re: Cold starting issue

Post by MarkD »

Doggy wrote: Tue Jan 26, 2021 12:04 pm The ecu will not initiate injection until it 'sees' a cranking speed of >60 rpm

Uneven running immediately after starting could indicate a glow plug problem - the glow plugs continue to operate for half a minute or so after starting to help even things out, (roughness is likely caused by not all cylinders firing initially). I accept this doesn't explain hot starting issues.

Excessive injector wear can also prevent starting, might be worth trying a leak off test.
Tried a new crank sensor (located beneath the thermostat cover) thinking that could be the issue, and a new battery as well..........it just laughed at me :lol:
MarkD
Newbie
Posts: 6
Joined: Mon Jan 25, 2021 12:33 pm

Re: Cold starting issue

Post by MarkD »

Success! EGR valve stuck open. Now blanked off, new starter motor fitted, good as gold.
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Doggy
Mod with a 2.2 HDi, De-Fapped!
Posts: 10710
Joined: Mon Oct 13, 2008 11:49 pm
Location: Northants

Re: Cold starting issue

Post by Doggy »

Well done. 8)

If only I could do that with the cursed Citroen and avoid stall roulette at every junction. :roll:
2002 HDi 2.2 Exec Estate, (2008-12) (wonderful)
2003 HDi 2.2 6-speed Exec Estate (2012-19) (also a gem)
2009 Citroen C5 2.0 HDi VTR+ Estate (godawful heap)
2008 BMW E91 330i touring (great fun - murdered by a reversing SUV)
2007 BMW E91 325i touring (slower smoother quieter)
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