Slow cranking 1HZ when cold (11 Viewers)

[athensrep]

Not ambient temp cold; when the truck is dead cold, the HZJ77 slow cranks on the first try of the day. After that, all subsequent starts are normal.

* new glow plug relay from when I put a new head on the motor. Glow plug system checks out.
* Batteries have tested as fine.
* It has a new alternator that I put in a few months ago. Charging system working great.
* I thought it was the old starter as it’s an old aftermarket unit. Replaced it last night with a new 24v from cruiser outfitters.
* I noticed the hot lead coming from the batteries to starter has some green on the copper; I’m guessing this may be part of the issue, but wanted to see if anyone has had this issue.

It cranks slow, pauses, then turns over fine and starts everytime, but it’s only on the first crank of the day when it’s a cold engine. Thoughts here?

 

[duncanrm]

Vague generic advice.. not specific to 1HZ.. sorry.. but:

How did you determine that the batteries were ok? Who tested it, did they have a vested interest in suggesting there were ok?

Any verdigris (green stuff) on the the copper cables is reason to give them some attention - I'd remake the main feed to your starter, and cleanup/remake your body and engine earths - nice shiny metal where they attach, good quality lugs etc - any old lugs should be given a thorough clean and scuffed up to remove grease and corrosion prior to reinstall, with your 24V system there's other considerations about the state of the series connection between the batteries together. The verdigris is actual corrosion, its not enough just to clean it off, the end of the leads will need to be cutoff and remade, or replaced if their length doesnt allow for it to be remade.

As for why it happens only when cold - I dont really know, everything is tighter when cold and batteries just dont perform as well either.

 

[athensrep]

Thanks for the thoughts on this. Really never seen this myself where the first crank of the day is slow.

I tested them both and they were at around 12.8V. The batteries test out OK, however chances are they are a bit long in the tooth. What I did not do is test amperage so I’ll give that a go today. Also, as far as the corrosion; that’s on my list as well. I clean up most all of the earth points on the truck when I was chasing issues with the alternator, but I’ll rerun a new lead from batteries to starter.

Thanks again.

 

[TheBussman]

you prob already know this but make sure you disconnect one of the batteries before your cold crank amp test. typically batteries will crank slower when cold and connections issues crank slower then warm. 12.8v means a fully changed and ready for a test.