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Cold weather starts at high altitude
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=5&t=73184		 Page 1 of 2
Author:  bigmaho [ Thu Jan 03, 2013 6:57 pm ]
Post subject:  Cold weather starts at high altitude
Hi Guys,
When I'm home, near sea level, the CRD is a little cranky starting in the morning when the temps have been in the teens and below, but it usually starts on the first try and if I give it a couple of minutes to warm up it's ok. BUT, I travel to Taos, NM often. Altitude at my place is 7300'. If it's been cold at night (it's often sub-zero F) it's very tough to start. It will crank and cough but usually die when I let go of the key. Black smoke pours out the pipe. I don't have access to power where I park, so I can't plug in the block heater. After 5 or 6 tries it will finally kick over and stay running when I let the key go. When I'm at lower altitudes (ie, Albuquerque, 5000') it starts ok even if it's just as cold.
Any ideas? My rig is a 2006 CRD, GDE tune, 140,000 miles (yes, new timing belt), Euro TC, I'm into this thing for the long haul.
Thanks and Happy New Year,
Billy
Author:  ATXKJ [ Thu Jan 03, 2013 7:11 pm ]
Post subject:  Re: Cold weather starts at high altitude
How old's the battery?

I drive up to Colorado on a regular basis -never have any problems starting.
Springs is about 6K - Woodland park >8K
Author:  06PeakBagger [ Fri Jan 04, 2013 12:51 am ]
Post subject:  Re: Cold weather starts at high altitude
Same as ATXKJ. Taos is a nice town but I get bored there, too much shopping. Or do you mean the Ski village? Spent a considerable amount of time in with the CRD in the Colorado Springs, Summit County (8,700) and as long as I wait till the Glow Plug light goes out it starts up. Maybe it is a little rough sounding for the first minute. I have never noticed a correlation between altitude and summer starting. Cold is what does it and takes away allot of the battery's releasable energy. If I am excited to ski or something I may not really focus on how cold it is. Check that battery.. Glow plugs resistance?

Or plug the Jeep in.
Author:  bigmaho [ Fri Jan 04, 2013 3:05 pm ]
Post subject:  Re: Cold weather starts at high altitude
Not a good morning. -15 last night. The battery is pretty new (10 months) but wore it down trying to start. Finally had to jump it. The extra boost got it going. Bought some diesel cold weather additive. See if that helps. Once it's started it runs fine. WHen I get home I'll check the glow plugs. I guess the resistance check is to tell if they are open/burned out? Anyone know if I'm looking for a specific number, or just anything other than infinite. Next question, do the make 'hotter' glow plugs?
Thanks for the responses,
Billy
Author:  papaindigo [ Fri Jan 04, 2013 5:16 pm ]
Post subject:  Re: Cold weather starts at high altitude
See Glend's post at viewtopic.php?f=5&t=43698&p=765400&hilit=resistance+glow#p765400 for resistance. I don't know of any "hotter" but IIRC some have had luck cycling the ignition on/off at about a 5-10 sec interval several times before attempting to start. Not sure why that would help but it may have something to do with getting the glow plugs fully heated up; worth a try.
Author:  mngoat01 [ Fri Jan 04, 2013 6:36 pm ]
Post subject:  Re: Cold weather starts at high altitude
Mines starts fine in the cold at lower altitude but when i hit the mountains for snowmobiling it doesn't start worth crap....i've always just attributed to the lower compression.
Author:  bigmaho [ Fri Jan 04, 2013 8:32 pm ]
Post subject:  Re: Cold weather starts at high altitude
mngoat01 wrote:
Mines starts fine in the cold at lower altitude but when i hit the mountains for snowmobiling it doesn't start worth crap....i've always just attributed to the lower compression.


Bingo. Either that or bad fuel / air mix. Less O2. I don't start as well either up here.
Author:  bigmaho [ Fri Jan 04, 2013 8:36 pm ]
Post subject:  Re: Cold weather starts at high altitude
papaindigo wrote:
See Glend's post at viewtopic.php?f=5&t=43698&p=765400&hilit=resistance+glow#p765400 for resistance. I don't know of any "hotter" but IIRC some have had luck cycling the ignition on/off at about a 5-10 sec interval several times before attempting to start. Not sure why that would help but it may have something to do with getting the glow plugs fully heated up; worth a try.


Thanks for this info. I'll pick up a VOM and check it here. I'll reprint the link here in case anyone else is looking....

In my experience that ETC light indicates a problem with the glow plugs. Suggest you check the resistance across each of the glow plugs to establish is one or more are dead or developing high resistance. You can either mesasure them at the plug itself, or easier to do measuring down the wire from the glow plug module connector located behind the battery. The wiring diagram is in the Service Manual, but its easy to see which four wires go to the glow plugs. Your looking for low resistance to earth, so using a multimeter, put th black lead on the engine earth or negative battery post and the red lead on the top of the glow plug or on the glow plug wire at the module connector (disconnected from the module of course). If it reads between a couple of ohms up to say 5or 6 then its ok, if it's high or open then the glow plug is bad and should be replaced.
Author:  bigmaho [ Sun Jan 06, 2013 1:24 pm ]
Post subject:  Re: Cold weather starts at high altitude
Haven't checked the glow plugs yet, but I added some diesel cold weather additive yesterday. It was -10 last night and +1 when I started it at 8AM. I tried the trick mentioned here to turn the ignition on and off a few times before cranking it. Between the 2 it started on the first try this AM. Phew....
Author:  Drewd [ Sun Jan 06, 2013 5:04 pm ]
Post subject:  Re: Cold weather starts at high altitude
I thought I had a bad glow plug but no MIL on, resistance on all plugs was within range but #3 was slightly on the upper limit of normal, and engine fired up only running on 3 cylinders for past couple weeks when temps were below 32 deg F.

I suspected a bad glow plug but a fresh battery allowed my vehicle to start up insantly this morning at 10 deg F temps. I guess the 23 month old Costco battery didn't have enough juice to power the glow plugs, the 300 watt fuel head bowl heater and crank the engine fast enough for it to catch on all four cylinders. I still think #3 is weak but it seems to put out enough heat where it fires and allows engine to run at idle. Before with weak battery, the engine would fire on 3 cylinders and I had to rev it up to 2000 rpm to get the 4th cylinder to catch and keep it up there for a minute or so before it would idle on all 4.
Author:  bigmaho [ Sun Jan 06, 2013 8:43 pm ]
Post subject:  Re: Cold weather starts at high altitude
how can you tell that the engine is only firing on 3 cylinders?
Author:  jinstall [ Sun Jan 06, 2013 9:10 pm ]
Post subject:  Re: Cold weather starts at high altitude
4000 -/+ ElPaso

Eh a little more to start but no big deal. Smae tune and TC. Nothig like when I was in NC and had 3 GP only. I did not plug in and it took almost an HOUR to get it started and it smoked like hell. So far so good here. last night at work is was 23.4F for about 10 hrr and was the temp when I started it last night, without plug in.
Author:  Dennis MacGyver [ Sun Jan 06, 2013 9:56 pm ]
Post subject:  Re: Cold weather starts at high altitude
Cycle the glow plugs about 3 times before attempting to crank. A shot of either might help too.
Author:  jinstall [ Tue Jan 08, 2013 12:51 am ]
Post subject:  Cold weather starts at high altitude
Personally I tell people to NOT use ether as most do not use it properly and use way too much.
Author:  Drewd [ Tue Jan 08, 2013 1:56 am ]
Post subject:  Re: Cold weather starts at high altitude
bigmaho wrote:
how can you tell that the engine is only firing on 3 cylinders?


Really easy to tell, 3 power pulses every revolution and one absent; it runs very rough. A good high compression CRD engine will idle on 3 cylinders but when cold, it is difficult to rev the engine above idle unless done very gently...Mine smoothed out on 4 cylinders at 2000 rpm and higher probably due to friction generation heat in the missing cylinder.
Author:  Drewd [ Tue Jan 08, 2013 1:59 am ]
Post subject:  Re: Cold weather starts at high altitude
jinstall wrote:
Personally I tell people to NOT use ether as most do not use it properly and use way too much.


yeah, its easy to get carried away with ether as I found out starting a 5.4L Triton 2 months ago and burned my eyebrows and a bit of my hair when it backfired ;-)
Author:  arengant [ Tue Jan 08, 2013 3:02 am ]
Post subject:  Re: Cold weather starts at high altitude
jinstall wrote:
Personally I tell people to NOT use ether as most do not use it properly and use way too much.

Plus, ether is like meth, once your truck gets a taste it will need a hit everytime you start it :lol:
Author:  jinstall [ Tue Jan 08, 2013 3:03 am ]
Post subject:  Cold weather starts at high altitude
Ether babies are not fun
Author:  dirtmover [ Tue Jan 08, 2013 9:11 am ]
Post subject:  Re: Cold weather starts at high altitude
bigmaho wrote:
Next question, do the make 'hotter' glow plugs?


This was the selling feature of ceramics but as we know "there's no gain without pain".

Dennis MacGyver wrote:
Cycle the glow plugs about 3 times before attempting to crank. A shot of either might help too.


I had a brief correspondence with Keith at GDE regarding how the GDE tune affects cold weather starting and one of the things he suggested was to cycle the ignition a couple of times before starting.

If the FSM is to be believed, however, the glow plugs should remain lit after startup for a period of time that is related to temperature so unless they're doing something funky with them and turning them on an off during the startup one would assume that they are on from the point the key is turned on and remain on until the temperature dependent holdon time is reached. I'm wondering if it's not just sufficient to wait an additional few seconds before cranking.

One thing for sure is that the dash "ready" indicator is not a direct indication of when the plugs are lit. Has anyone measured the voltage or added an indicator to monitor when the glow plugs are actually being powered?

Additionally, has anyone seen an incidence of plugs failing without lighting the CEL? They have the circuitry to measure current so I would guess not.
Author:  GreenDieselEngineering [ Tue Jan 08, 2013 12:46 pm ]
Post subject:  Re: Cold weather starts at high altitude
The glow plugs do through a "push" phase when the key is turned on, this lasts for about 2 seconds max. Then they go to a readiness phase at lower PWM to maintain temp. Once cranking starts the PWM is bumped up a bit to compensate for fuel cooling the tip. This is difficult to optimize. The key cycle trick helps as you get a couple blasts of full voltage from higher PWM duty cycle to heat the plug to maximum before cranking.

An instrumented glow plug would be ideal to optimize the PWM duty cycle for various temps and altitudes. GDE
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