What's the best way to start a Cummins that's just too cold? I plugged it in, and it was still too cold. It just won't turn over. It runs great (bad parts aren't the problem) but just won't start because it's too cold. So, what specifically should I do?

 

How cold is too cold? First make sure the batteries are fully charged, Clean the cable connections. If it still does not start, get a good DVOM and get a battery voltage reading while trying to crank it. That will tell us where to go next. Too many possibilities at the moment.
What kind of oil is in it? Are you using fuel conditioner? How long have you been cranking it at one time? How old are the batteries? What is the cca rating of the batteries?

 

Take a broomstick or something similar and tap the starter, see if it was just bound up. Could have just frozen overnight. Hemi Cat was right when he said to measure the voltage of the batteries, both before and during crank. It is cranking right?

 

Yes it's cold here now. How does it start when it's warmer, in the thirties? If you are plugged in outside with our temp in the teens now, the block heater may not raise the block temp very much. You could try stuffing insulation around the engine to prevent heat loss. Assume you are cycling the manifold heater twice? Strong batteries are a must if you park outside, also be sure your idle is set for 750 rpm or better and give it a little throttle to start.

I park in my garage where it rarely freezes and plug it in for two hours before I need to start it. It starts on the first revolution with fairly new Optimas and Rotella 15-40. It will also start at 0 degrees not plugged in out in the weather if I cycle the heater twice, runs rough for a minute.

If you can't get it going call me 303-940-1639. I don't know much about 24-v models but we can talk. Where in Colorado are you?

 

That's where I'd start.

If they are the original batteries, they are way overdue for replacement.
You want to get 2 new ones with at least the cold cranking amps of the OEM's.
Yes, replace both at the same time or you'll be stuck in the loop of replacing one each year for eternity.


phox

 

Its not too cold - I live on the Canadian prairies - where it actually does get cold. With good batteries and a few hours of being plugged in, the CTD will start at -35 or -40. So the cold really isnt the problem here.

Id look at the batteries and then the fuel system (specifically the rubber fuel lines from the tank to the hard lines and from the hard lines to the IP), as well, there is a fuel filter pre-filter. have you changed it recently?:

http://www.dodgeram.org/tech/dsl/fil...filt_clean.htm

 

Is this on 24V's also? I have 177K on my 99 & neverheard of the pre filter, it seems like from the way that the write up was talking that it was on a 12Valve truck but i'm gonna go look for it..

DRecu!

 

Um, Dr. Evil is going to bed.....

I thought he had a 12V......I just seen the 98 and assumed it was a 12V'er. The prefilter is on the 12V.

 

LOL yeah thanks I figured it was just a 12V thing, naww I am not going anywhere tonight lol i'm not that obsessed! it can wait till tomorrow!!
Thanks!

DRecu!

 

Ok I'm having a similar problem trying to start my 96 but I'm only in the mid 30s. It fires right off but as soon as I release the starter it dies. I can go with some pedal or with none and it does the same thing except that as long as I stay on the starter the engine will rev with the eccelerator. It took about 40 tries this morning to finally get it to run. I had to put my 200 amp charger on and set it to "jump" and even then it took several tries and I still had to give it about 1/2 throttle and hold the starter for several seconds with the engine reving the whole time. I don't have a block heater and until now I've never needed one.
I really don't think it's batteries but it could be. The starter seems to spin the motor just fine and it does kinda start when it's spinning but it dies the instant I let off of the starter.
Don't know if there is any connection but this is the first winter since adjusting the star wheel (I think about 20 clicks) and installing the #10 plate.

 

Also could it be my intake heater and if so how would I test that?

 

Easiest way to test is to look and see if the voltmeter drops when the wait to start light is on. 30° is nothing for these engines to start in.
I think the real reason for your hard to start is that the shutdown solenoid isn't lifting all the way because it's corroded/dirty or your batteries aren't up to snuff.
My 200 amp charger won't start a cold Cummins on it's own without first charging the batteries for awhile, same goes for jumper cables.

 

Actually, I got it started. It was -5 and the fuel had gelled. I put some antigel in it and jumped it with my dad's new 4runner. It took a while, but i got her kicken. I definetly have to replace the batteries now, but that shoud help. Thanks again for all of the suggestions.

 

So weak batteries or corroded terminals will keep the solenoid from engaging all of the way?

The terminals were in pretty bad shape.
I've cleaned them and have a charger on it to make sure the batteries are hot. I'll try it again in about an hr.
The batteries are 2 yr old, 75 month, NAPA LEGENDs
I couldn't find the cranking amps anywhere on the battery.

 

Not necessarily, mainly the engine isn't cranking over fast enough even though it sounds like it is.