z51vett

Auto zone will check you charging system free. If you have some kind of short or drain I don't know if they can tell. Short trips will not charge the battery back to full charge, need about 30 minutes at least 45 mph to get charge backup.
z51vett
Doug

forg0tmypen

Ok. Some updates. Finally bought a multimeter. Battery sits cold with 12.5 volts. CCAs were at 650. I started the car in the morning and it fired up fine. I let it idle for a good 5 mins all the while alternator was holding steady at 14.5 volts. Shut the car off and whet to restart it and it wouldn't fire. Tried again and it was having a hard time starting making a ton of noise. So I GAVE IT SOME GAS and it turned over ferociously. Don't know what this means... I also took the multimeter to the charge nut on the alternator and it was showing 14.56 volts same as dic reading.

I have a theory, I think due to horse power mods (ported TB and Manifold, cam and springs, and a tune), the stock manifolds are getting hotter than stock and heating the starter. The car only has a hard time starting when its hot it seems. I needs a minute to cool before it will start again is what the problem seems to be so far. Just my uneducated opinion. So I was going to insulate the starter and see what that does. Feel free to chime in...

My list of things to check:
Heat soaked starter
Leaking injector
Tune related to Start up air flow table or cranking VE table, or both
Bad starter

Gary '09 C6

do you think there is a fuel delivery issue at start-up when the car is hot, and off ?

your comment above about "giving it gas" has to be a clue to the puzzle...something about your tune, perhaps ?

forg0tmypen

I think that might tie in with the hot starter? Its not able to turn the motor over on its own once it gets hot? I did some more reading and found that people with cammed cars had a hard time getting the car started after initial start-up due to the starter getting hot. Some insulated the starter and others were tune related as you suggest. Im guessing its a little of both in my case. Ill call my tuner on monday.

SUPERCRUZ

You have opened up a whole new set of variables now that you noted the custom mods done to the engine. You did not mention headers which would throw a lot of heat around the starter but with stock manifolds, still good to check a heat soaked starter issue. Having owned a H/C C5 coupe for a number of years, I had a lot of issues with hot start. Like you, I would drive the car and upon parking and coming back to it a few minutes later, it would turn over but not fire. My tuner had to mess with the tune quite a bit to get the air flow correct at higher intake temps. I will say it was a bit of a bear to chase this problem down with multiple tuning sessions and a lot of data logging. I would be more suspect of the tune than your battery or voltage at this point given all the tests you have done on the voltage. I really do not see anything suspect with the readings you are posting on the voltage side.

chetly

While wrapping the starter could keep heat a way for a while, once it gets heat into it from metal to metal contact and the other heat around it, it will take even longer to get the starter to cool off. If your going to wrap anything, I would wrap the header. That's why wrapping headers voids the warranties from all the major manufactures, it keeps the heat in the header and doesn't let it escape.

ATC399

13Z bone stock takes longer to start (slow crank) when hot...Close to 6k on her...

1320IN9

could be tune related, have your tuner check airflow on start up, and check for a leaky injector, my cammed supercharged z was having a hot starting issue that i chased for over a year, never even crossed my mind to check for a leaky injector till someone suggested it, reason i never thought of checking in the first place is because they were brand new $900 ID850 injectors with less then 300 miles on them, well turns out i had a leaker.. they replaced all 8 for me under warranty.. all is good now. i would start with checking yours, should take no more than 45 min to check.