Well yesterday I decided to take a little spin in my '72 and after charging the battery up (been sitting all winter, wanted to start full), off I went. When I backed out of the garage, I stopped to put my ramps in place in case what is going to happen, happened. After my 30 minute drive, I returned home and parked it on the ramps, knowing darn well when I shut it off it would not restart. I was 99% sure it would start later in the evening or in the morning, and being on ramps it would be in the right place for it so I could cover the starter to protect it from heat. Well, after the drive it would not start, this morning it started right up. Has to be the starter right? Last night after the drive I had 13 v at the battery. Battery is not the problem. Has to be heat bothering the starter right? That's my next step, will let you know. BTW, all the grounds have been checked and are clean and strong.

 

Clean your battery terminals and then tighten them well before going off on a wild goose chase. For real.

 

Maybe - might want to run a load test on the battery to make sure it's got the amps to meet the demand.

It makes no sound when you turn the key or cranks very slowly or what?
GM starter?
Small block?
Stock exhaust or headers?

Could be heat-soak of the starter — electrical resistance rises with heat. There's a GM solenoid heat shield that I have on my BB w/stock manifolds. Kinda helps to keep direct heat absorption at bay. Not sure if it also fits SB.

 

Thanks, just put a quick disconnect on one side, other side was also checked.

 

makes no sound, gm starter professionally rebuilt few years ago, small block, stock exhaust, need to check the tailpipes for bananas lol

 

I would check the other side of each cable as well. Specifically the ground of the negative cable on the frame. Take the bolt out, and clean the frame so you’re sure you’re attaching to good metal.

 

Thanks, did that several years ago.

 

In reference to keeping the heat off the starter: is the solenoid the specific piece that needs protection, or the entire unit, starter and solenoid. I assume that the click that many often hear is the solenoid 'kicking in' but being unable to spin the starter? Thanks. PS, years ago I also wrapped the exhaust from the manifolds back with something designed for them, from DEI or someplace like that....

 

There is a Heavy-Duty Solenoid that cost a little more than std. They fit the old style GM starters.

I found one at NAPA. It will have a brown end cap on the unit. That brown piece is ceramic, and ceramic handles the heat much better.
Supposedly it won't weld itself in the ON position. (or off)

Been several yrs with mine. No issues.
However, I do run an insulating starter wrap.

And for what its worth. You stated you have 13 volts at the battery. That's wonderful.
It's nice to know the ALT is kicking-in the voltage.
However, it's not the 12v that starts a car.
It's the 600 - over 1,000 cold cranking amps that does that.

 

Clean the battery connections. Or just go off on your wild goose chase. Voltage reading means nothing. You need to get it load tested.

 

Or try this! Take the solenoid off the starter and remove the end cap that heads up referred to. There’s a big round washer inside. That’s probably all carbon up clean it with a wire brush iand your start won’t start issues might go away.
Be careful taking the end cap off there’s fragile wires inside. Don’t pull it too far if you break them, you’re screwed.

 

I had a similar problem once upon a time. Got hot and didn't want to crank, nothing not even solenoid click. I chased that around with the starter, grounds,battery connections, solenoid etc. And it still did it.
Finally I looked at the neutral safety switch. That was it. Haven't had a problem since.

 

My work was all in vain. After a nice one hour drive, no start. Grrrrr. Goin out to dinner now, it'll start when I get home gauranteed.

Will look at the safety switch. Battery was new 5/23 so doubting it at this point. I'll do anything to avoid removing that starter but if I must, then I must. Getting to old up for this nonsense haha

 

Have you checked your engine's timing? If the timing is retarded, the engine will run hotter and thus possibly "heat soak" your starter motor. If the timing is too advanced it will make the starter work harder. Verify that your vacuum hoses are working and the vacuum advance is actually moving the timing.

How old is the starter motor you are using? Is it a standard factory style unit? I have switched my 1968 BB to a gear drive starter and that alone solved any heat related issues with my starter. I have never had to wrap anything on my highly modified 427 to help it start when hot. The gear drive I bought was from Summit and has worked well for decades on my C3.

If a heavy duty solenoid is available for this type of application then it might be worthwhile to try before spending all the money on a gear drive starter. I personally would just make the swap to a gear drive and rid yourself of any more aggravation.

There are ignition boxes and even EFI software that will allow you to pull a specific amount of timing from the ignition system while cranking the engine. "Pulling timing" unloads the starter allowing it to spin faster as a result. My MSD ignition box can do it as it has become a common feature that people want when they have a heat soak issue.

No matter how old your battery is I would isolate it and charge it completely. You want the battery to "gas" off a bit before tasking it off the charger. The reason I say to "isolate" the battery is so that you don't damage anything electronic if and when the battery voltage gets above the maximum allowable input voltage. I have seen batteries charge at up 15,16 and 17 volts and that will damage many electronics, permanently. When the alternator's voltage regulator "fails" it can do terrible damage if not caught soon. Cheap battery chargers can do this very easily so be careful and don't buy CHEAP battery chargers.

I would be very careful saying that it is the current in the battery that "starts" the engine and not the voltage. You need both the 12 volts AND sufficient current inside the battery to make that starter spin. 2 volts with 100,000 cranking amps will get you no where. The same goes if you have 8 volts of battery voltage but have 10,000 amps of current available, it is the voltage that will stop you from getting the motor to spin fast enough for the engine to start.

 

Thanks, I shall recheck the timing; pretty sure it is set at 12 but don't remember what that made it 'all-in'. I know factory says 8 but I read that it run better if set higher (and it does). Now it seems it might be part of my problem ugh.

 

Next time the car is hot and on your ramps jumper the TOP BIG terminal on the solenoid to the 'S' terminal, if the engine turns over every time then check to see if the NSS is out of adjustment.

 

Are these the 2 points used to hook up a remote starter button? Thanks

 

Yes.

 

Easy way to verify your grounds is to run a common jumper cable from the battery negative terminal at one end then clamp the other end right on to a clean unpainted engine block spot. With the engine warm it might not crank well. The extra ground cable will confirm or eliminate the grounding issue as the problem. If it helps, bad grounding connections is the problem.

 

My car show buddy bought a C3 that had been sitting dormant for several years. He is a professional copier repairman and obviously very technically competent. Somewhere along the restoration journey, he rebuilt the Quadrajet among the other systems. It’s been about 5 years and he still has trouble starting his car after the engine gets hot. I won’t go into the 15 different things he has done to remedy the “heat soak” problem, but he still has the same issue. The money he has spent on all THE FIXES would cover Lars restoring the carb five times. Send your carb to Lars, or you can do like my buddy and keep trying new FIXES and WASTING more money. The last fix was to pull the intake manifold, he told me there was something about the gaskets were not being correct????