My brother has a 2002 trans-am. The battery went bad,so we put a new battery in it.Went from a 525 cca, to a 565 cca. Now it will crank over all day long , but it wont start. If we put jumper cables on it, it starts right up. I dont have a clue what it could be, which is why I came here. Does any body have any ideas? Please help. Thanks in advance

 

maybe the new battery is sh*t , take it back and have it tested

 

525 is a V6 battery, LS1 should be a 690 according to my helms. My original AC Delco was a 525 from the factory for some reason - only lasted 33 months here in Florida.

 

Well we put a bigger battery in (700cca), and it did not help.The engine cranks over plenty enough to start but it just wont fire over. He reset the computer by turning the ignition key on, and off a few times and it started right up, several times even, then it went right back to not starting again. Now it will only start one out of even ten tries. It has gas in it,I dont know what the fuel pressure is, but it squirts out pretty good. we checked various wire connections, and still nothing.I dont have much experience with these cars and i am scratching my head pretty hard. Can somebody help me before i scratch out all my hair?

 

Never heard of resetting the PCM by turning the key on and off a few times? How did the battery die, ignition wasn't left on and the battery left to die was it? Doesn't sound like a vats problem if it's turning over every time, so has to be something else - any way to see if it has a code/SES on?

 

i had a similar experience like that but not from a dead battery. mine was ignition relay. started whenever it wanted to, several times in a row and would die when it wanted to or not start at all. check for spark on any of your plugs. also might have a small chance of a crank position sensor.

 

Try a PCM reset this way:

Turn key on, don't start car
Pull PCM BATT and PCM IGN fuses in engine compartment
Wait 5-10 min
Turn ignition off
Replace fuses

(This will clear any current or stored codes though).

Also might find an answer at www.gearchatter.com/viewtopic9317.php

 

I was thinking possibly CKP sensor (relearn) too, that's why I asked how the battery died/any codes. I've had two batteries go dead on me, both times just replaced it and only issues was a grumpy idle until it relearned.

 

Sounds to me like an ignition switch problem. Or could be an engine ground problem.