Slow crank with good batt and connections?

[Dirtman]

Truck 2009 2.3 auto 67k miles. Battery is 2 years old 590cca and voltage tests at 12.5 engine off, alternator running at startup voltage is 14.4, current draw with engine off is 80ma with sjb still on 25ma after an hour, ohm test ground to block is zero, positive to starter is zero.

Issue started during the insane cold so I just chalked it up to battery being cold (had to jump it each morning below 5 degrees but it started fine with a jump). It was 50 today and the truck still cranked slow this morning... so now im certain something is actually failing and not just a cold related issue.

Thoughts? Im thinking starter but in my years starters just flat out fail... never had one go out slow?

 

[HighMileage93]

That 590cca seems low to me. My 93 2.3 calls for a 850cca battery. Could have an armature going bad in that starter though. It won't cost you anything to get it checked at least.

 

[RonD]

Yes, +1 ^^^

See what battery voltage is when Cranking over engine, should stay above 9.8volts, above 10v is best.

Under that and amp draw is too high, could be cables or starter motor

You can disable fuel pump by pulling FP relay for a No Start and longer cranking
Fancy name for this test is a Load Test

12.5v on at rest battery(after it sits for at least 4 hours) means it has 75% of its rating
So 75% of new CCA

12.3v is 50%, and time to look for battery sales, lol.

 

[Dirtman]

Oem battery was 575cca, i have 590cca (not ca) I originally thought the same, battery was cheap low amp... (not ruling out a crap battery just giving specs). The truck also starts fine after warming up. I even did multiple starts and shut downs after warm. Did clear engine flood mode (held the pedal to the floor) and let the starter run 10 secs after warm and it cranked like a champ. The slow crank only happens on cold starts.

I have an old shcumaker spelling? Load tester ill throw that on it in the am. It can do a dry load test but also check volt drop when starting. I left my hood open to check battery voltage overnight without setting off the sjb by opening the door. Ill do all those test and get back...

 

[91stranger]

I would see about taking it somewhere to have a battery tester do a load test. We have brand new batteries all the time that go bad after a few months. Normally from people not disconnecting them like they should when they sit but new batteries can go bad too. I assume the CCA drops a lot when you go to actually crank the engine and that is why it will not start. I would think the issue is specifically with the battery since you say it will jump start fine.

 

[Dirtman]

Just wanted to give an update. I charged and load tested the battery, checked out perfect. Did another parasitic draw test just to be sure, also perfect. Cleaned all the cable connections and terminals, perfect. So I took the starter off and took it over to advance auto to do a bench load test on it. It wizzed up and the bendiz shot out good but the fancy pants computer said it was drawing too much current for whatever reason.

I replaced it and the truck starts faster than it has in at least a couple years. Definitely a first for me having a starter fail "partially" like that... In 30 years ive only see them just flat out die one morning.

 

[alwaysFlOoReD]

Thanks for the update.

 

[rusty ol ranger]

Ive had a couple do that.

Not so much on smaller engines, but on my big ol V8s

 

[Shran]

The starter in my F150 has been doing that for quite a few years now. But it happens when the engine is warm. I'm sure it's a starter issue, have replaced everything else. I should fix it but I've only put maybe 200 miles on it in the past couple years so it's not a huge deal, I just try to park facing downhill in case I need to roll start it, haha

 

[Dirtman]

Ive had a couple do that.

Not so much on smaller engines, but on my big ol V8s

And oddly enough I think I have 4 or 5 reman 429/460 starters laying somewhere in my basement from my many failed projects over the years...

somewhere I still have a fresh bored, line honed, tapped freeze plugged, porcupined and girdled 460 block packed in oil... I need to clean my basement.

 

[holyford86]

...Definitely a first for me having a starter fail "partially" like that... In 30 years ive only see them just flat out die one morning.

A friend of mine is a starter and alternator re builder. he has told me in the past that the gear reduction ford starters will have 2 of the 4 brushes fail and cause issues like that. Being a fleet mechanic in the northeast, what i have seen bring them down 99 percent of the time is the braid between the solenoid and motor rotting out and burning off.