The Stovebolt Site Forums The Shop Area The Electrical Bay slow cranking when hot

51 chevy w/59 235, 12 volt battery not sure about the starter.It cranks fine when cold.Even when it's below freezing. Once the engine reaches operating temperature however it cranks real hard. Brand new battery.Foot pedal crank. Sounds to me like my starter is hurting. Could this be anything but the starter? Timing? Just grasping at straws.Starters aren't cheap. thanks---Jack

Retard the timing just a little at see if that helps. Makes sure all the battery connections are clean. Load test the battery. Some times they will work okay cold, but fail when hot.

Some times starters do get slow when they are hot.

You could check to see how it turns over with the ignition off or the coil wire off. If the timing is presenting a problem it will turn much faster with no spark.

Exactly right. Glad you thought of that.

I like that one too. I hadn't thought of that.

Double check the battery. With the engine hot there is still compression on the engine and the battery (or starter) may not be up to the additional strength needed to turn the engine with compression on it. I've seen this happen a few times in my days.

99% of the time...it's the battery

Battery will fail more often when hot than when cold. We just work them harder in the cold. If the battery is hot it has a problem. Most often material has been pulled from the plates and is now shorting them out at the bottom of the battery. A load test will reveal a bad battery in short order. Since it is not quite summer, in most places. I think you are gonna find the battery is headed to where ever battery heaven is.

Battery is brand new.---Jack

I've seen new batteries fail. Have it checked just to make sure.

Bet ya just have bad bushings in the starter.
DG

I will. I have some testing to do.Gotta get all the bugs out so I can drive this thing.---Jack

There are four things that are unacceptable: Leaky roof, backed up toilet, out of beer and Truck won't start.

How can I find out if that is so? Is there a way to test them? I guess it wouldn't hurt to remove and inspect the starter.---Jack

One bolt, two nuts and you got it out on the work bench.
Rebuilding kits are available or you drop it off at the local
starter/generator rebuilder and let them rebuild it. They have
the tools to do it right.
Any decent auto parts store or farm supply can test your battery.

Denny Graham
Sandwich, IL

dead cell in battery for my vote, been there

One thing not mentioned is the battery cables. I had issues with my old farm tractor. The ends looked good and the connections were tight, but after 60 years, the wire inside the insulation was badly corroded and causing me all kinds of grief. I found this out after converting to 12 volts, replacing the starter and switch and nearly ripping my hair out. If your cables are very old, it is a possibility.

I learned valuable lessons after months of back and forth with a similar issue...
Replaced
1 battery
1 starter
1 coil
1 plugs
1 +/- leads

Buy parts local and avoid mail order hassle if parts don't fit
Buy quality napa parts worth the few pennies extra
Replace the cheap stuff first
And most importantly:
Check the grounds


When I ran out of options and replaced my +\- leads on the battery I found out that the ground was loose. Incidentally it was attached to my exhaust manifold so when it got hot the grease melted and made its way under the lead. I have since experienced the issue again but at that point I added a body ground into the mix. My issue got so bad the truck would only start when there was high humidity.

Tried it again. Got the motor hot.Shut it down and tried to restart it.Same thing.Pulled coil wire,same thing.Not the timing.Checked the cables. The ends were hot. I'm onto something. I cleaned all connections.Checked for good grounds.Tried again. Still cranks too slow to fire.
This is a long process with me only getting a few hours on the weekend to work on it but the starter is coming out next and I'll start there.Also,I'm convinced it could be a defective battery so I'm going to take it to someone who can load test it.Thanks for all the ammo.I needed ideas.---Jack

How old (and what size) are the battery cables? As someone pointed out, they could be corroded in the insulation and you not see it.

May be a bad battery, and then I have seen starters break down once hot.

Cables are the best I've seen. Clean, solid ends and heavy gauge copper wire.I took apart the starter a little and found the switch contacts needed cleaning and aligning.The brushes looked good as well as the end bushings but I dumped out a pile of dirt that got inside somehow. Already an improvement. It cranks faster when warm.
Now there's something else going on. I gotta figure why it stalls when it gets warm.Maybe a fuel issue,maybe ignition. It's been so long since I did any of this I'm having to learn all over again.---Jack

Good deal on the starter. Tackle one thing at a time. When it stalls, see if just a little gas down the carb will make it fire up. If it will then likely fuel.

If a little fuel doesn't help, then check the spark.

I found the problem that was causing my starting issues. I got it to crank better by cleaning contacts but that wasn't the reason for hard starting. I narrowed it down to fuel.No squirt of fuel at acceleration.I removed the bowl cover while it was still hot and it was full. Accelerator pump pumped fine. Then I noticed there was no opening in the gasket where the fuel from the accelerator is pushed up to the bowl cover. The new gasket that came with the kit was missing that hole. I still had the old gasket so I wiped oil on it to puff it up alittle and put it back in. The truck started right up.I did a little adjusting to get a good idle and shut it down. It started right back up so I took the truck for a little spin. That is more like it! Truck responds nicely. Now I can drive it around while I finish up all the little accessories. Thanks for all the ideas---Jack

had you just rebuilt the carb??

Yes. Only ran it for a few hours in total after the rebuild. And I cleaned it good.Soaked everything in cleaner and blew air to dry it after rinsing in water.

Probably made by the Hop Singh gasket company.

just curious because the first start of the thread did
not indicate that but...I thought it had been running great all the time and all of a sudden it started the hard to start after hot.. at any rate, glad you got it running the way you want it

when you buy a new battery they are not fully charged usually only 65 to 70 % even though the guy at the counter will tell ya oh yeah we charge all our batteries b.s. unless you see a battery charging station where they have their battery rack usually right behind it look around the corner to see if there are any batteries on a multiple charging station most likely not. they unload em off a truck and sell em. the specific gravity of a fully charged battery 6 or 12 volt will be 1.280" at each cell you can buy a specific gravity meter for cheap. 1.0" is the specific gravity of distilled water so if you have to add water use only distilled water not tap water. when i buy a new battery unless it is an emergency i charge it at low amps for a couple days.then i check the gravity.on a normal battery with lead plates once you hook it up and draw juice from it that will "set the plates" so if it is only 75%charged that's all it will ever be charged no matter how many times you charge it. an agm {glass mat] battery will take a fresh charge up to 100 % when drawn down or not fully charged when installed.the fiberglass mats are not like lead plate batteries they are mostly used on motorcycles which take a hell of a beating.but they have em for cars too.

Hmmmmm- - - - - -interesting theories, especially about "setting the plates". Where did that idea come from?
Jerry

Not to pile on, but Hmmmmm------

That's the second time I've heard that "setting plates" business in 3 weeks. I've always put new batteries right in the vehicle and took off. Not that I don't believe you Mark, but one would have thought over 50 years would have heard it before. Have you found any good documentation of the phenomena? By the way, the next battery I bought I put on the trickle to get it from 70% up to 100%....more of an experiment than anything.

I've always put batteries right in and started using them, if it was only part charged the ammeter would have pegged for an extended period .... has never happened, work fine from the git go and always work fine for years, hot or cold .... OTOH, we're not talking Harleys here, those dealers and their batteries may come from a different planet besides, the OP found and fixed various problems, none of which involved the new battery

Bill

When buying batteries, always check the date code on it. Should be fresh, or a month old at most. If not, don't buy it. I once found one at a battery dealer over a year old. Date codes can be found on the internet it your not used to them.

these are not theory they are facts i am a retired harley master tech.with 25 years experience.all batteries 6 or 12 volt produce 2.1 vdc to 2.12 vdc per cell all batteries are wired in series thus producing the voltage of a battery 6 volt has 3 cells 12 volt has 6 cells.specific gravity is the comparison of gravity of the earth itself or density. a solid or liquid. sulphuric acid is very dense and is diluted with distilled water to a specific gravity level. shall i continue with the class?specific gravity is checked at 77 degrees with a correction factor of .001 for every 3 degrees in temp difference s.g.+.84= cell voltage.when charging a battery the max temp of the battery should not go past 120 degrees. check it with a heat gun,put your hands on the case of the battery if it's hot when charging give it a break for a while or this is also a sign of a bad cell .050" difference of gravity between cells indicates a bad cell and the battery is toast. the main thing is keep connections clean & tight use a electrical contact grease on the posts and connections, keep the battery case clean a dirty battery will self discharge faster than normal.normal self discharge rate is.5 to 1 % every day so if your truck is not a daily driver keep a trickle charger on it. bikes tend to sit a lot now days people buy them to show off on the weekends.they can't understand why the battery went dead.replaced a lot of really good batteries that went bad simply because of neglect.i get 6 years out of my batteries in all of my vehicles because i keep up the maintenance also the fluids will absorb water from sitting or running for a short time only. the worst thing you can do to a motor is start it up in the drive way run it a few minutes and shut it off the condensation immediately starts in humid condition's especially.take it for a drive that's what it was made to do be driven. after 25 years of listening to whining customers and tryin to beat it in their heads i know my stuff.bike or truck

in reply to were not talkin harleys here. that old gm product you are driving has delco remy parts in the electrical system just like old harley's had up until 1970.generators, regulators, points & condensers,connectors etc.yes check the date codes on the battery you buy. all batteries are made by about 3 companies these days regardless of what they go in. and yes most part on harley's are outsourced just like your new car or truck thats's why we don't have a work force anymore.also the term "setting the plates" refers to the sulfation that starts inside a battery as soon as it is hooked up and energy is drawn from it. a battery that is 70 %charged will start and operate your vehicle but it will stay at 70% unless it is a gel or agm type battery which can be charged to 100% after energy has been drawn from it. check it with a hydrometer and see what it says that is a fact of the state of charge in the battery 1.210"s.g. 0% 1.260" to 1.280"s.g. is 100%. not tryin to start a argument just tryin' to explain things and help.

Harleys are like hound dogs- - - - -they like to ride around in the back of a pickup truck- - - - -good thing we like to keep our stovebolts running well! Can you come talk to my garden awhile, Mr. Harley dude? I need some more fertilizer!
Jerry

Specific gravity has nothing to do with the earth! For liquids, it is a comparison of the density of the fluid with that of water!

what holds that water in place? gravity. yes specific gravity is for liquid density. my harley has never been in tha back of my 54 chevy pickup which i have owned for 40 years but my chevy pickup has been on a tow truck a few times torque tube woes only bad set up from the get go that stuff is all gone been updated to newer style goodies.

Your bad luck with a 1954 truck is unfortunate. They can often be very dependable.

Common misconception. Density has nothing to do with gravity. It is a relationship between mass and volume. Mass and volume will not change, even if you are on the moon (or those astronauts in space would look mighty funny). What will change is "weight" which is created by the gravity pulling on that mass. Specific gravity is a ratio comparing two densities. Hope that helps.