Cold Weather and Slow Cranking

[Bushwakd]

Going on the second year now with slow cranking on start up in cold weather. I have fresh batteries (DEKA brand) that are a year and a half old. New alternator when batteries were installed a year and a half ago. New Motorcraft glow plugs and relay were put in late spring this year. Injectors were freshened up by Swamps late spring this year. Compression was checked before injector install and was in the high upper 390-400 psi. Battery cables look to be in good shape with no corrosion.

What am I overlooking?

Today I disconnected the batteries and put a multimeter on them and got 12.53 volts on both. I then pulled the batteries before starting the truck and took them in to Advance Auto to test.Test turned out good. I took batteries home and put back in the truck and tried to crank it over and get a weak spin out of the starter. It starts but cranks slow. Once it is started it cranks over fine every time.
What I do notice is first start up of the day in cold weather I turn the key on and the dash battery gauge gets dragged down to 8 volts (glow plugs being energized and vacuum pump running and fuel pump running). I wait until all the power robbers are done sucking power and crank it over and the starter spins slow. I drove the truck to Advance Auto and they did a load test with the batteries installed and batteries pass, alternator passes, starter spins normal and passes.
Why does the starter spin slow on the first start of the day or after sitting for an extended period in cold weather but spins fine after that when everything has warmed up? The starter is the original starter and has 117,000+ miles and is over 12 years old and has never had extended cranking issues except for several injector installs.
I want to think the issue is the starter but why a slow cranking starter on initial start in cold weather but starts fine after that. Yes I can plug it in and it helps aid in starting but that does not answer the slow crank issue.

Have I figured out my own problem by narrowing it down to the starter?
I guess I need to pull the starter and have it tested next.
To simulate the slow cranking in cold weather do I need pull the starter out and put the starter in my freezer for 8-10 hours and then put it in a cooler with ice packs and then take it to my local starter rebuilder for testing to see how it reacts in cold weather.

 

[907DAVE]

Test your starter amp draw when cold...that will tell the whole story.

And be sure to have it tested while still on the truck, free spin on the bench will tell you nothing.

 

[Tom S]

I think you have a starter issue most likely.

 

[abbottfarms]

Mine had a similar issue a couple years back. Slow cranking, eventually led to eating a few starters. Ended up being the power feed from the batteries to the starter. About 8 inches up from the starter it was corroded. New cable, no more issues.

 

[Bushwakd]

Test your starter amp draw when cold...that will tell the whole story.

And be sure to have it tested while still on the truck, free spin on the bench will tell you nothing.

Okay I will check that out. Thanks

I think you have a starter issue most likely.

That is what I was thinking when it started to crank slow last winter. Here I am a year later same starter and the cold weather slow cranking blues.

Mine had a similar issue a couple years back. Slow cranking, eventually led to eating a few starters. Ended up being the power feed from the batteries to the starter. About 8 inches up from the starter it was corroded. New cable, no more issues.

Thanks, I will check the cables out. I did crawl under there the other day and took a peak at the starter connections but I guess I will have to look a little closer at the cables further up.

 

[Zaairman]

Try 5w40 oil. :thumbsup:

 

[superdutyman97]

My 97 does the same thing and I've went the same route new batteries starter and checked the cables. I even went as far as replacing the terminals. I've since wrote off the issue to the remn starter from autozone. I would put my money on the starter

 

[Bushwakd]

Try 5w40 oil. :thumbsup:

Putting that on the list for the upcoming weekend to do list.

 

[Fly By Night]

I had more or less the same issue I ordered a gear reduction starter from the member GTO killer that mf'er will just about redline the thing (well it sound like it), It is money well spent I promise, and IIRC cheaper then a set of Deka batteries

 

[stroker2]

Mine is cranking slow as well. New batteries and the cables are good. Turns over slow but even at 15 degrees and not plugged in, it will fire right up....but it is a slow crank. My guess is you need a starter given that its the original.

I had more or less the same issue I ordered a gear reduction starter from the member GTO killer that mf'er will just about redline the thing (well it sound like it), It is money well spent I promise, and IIRC cheaper then a set of Deka batteries

Holy run-on sentence. :slap: I barely made it through that without turning blue

 

[dmd]

You can use a set of jumper cables to run along side the positive cable, just parallel
what is currently there. Use the clamps to connect to the posts.

If it starts way better then you know you have a bad cable.

 

[ParkerFly]

If you do have to change starters those gear reduction ones are a beast. It sounds like they turn the truck over twice as fast as what a stock one does, even in tip top shape.