Okay here's the deal. My z28 died while driving on the freeway would not start again. I had it towed home and started researching. The car would crank but wouldn't start. Has a new opti new plugs new wires . So I pulled a plug and tested for spark which there was not one . I narrowed it down to the icm. Replaced that now car will turn over run for a second and die. Has aaa come out and try to jump me. It did the same thing although the aaa guy tested my battery and said it was dead. I don't know what would be wrong the battery shouldn't stop it from running especially cause I have a new alternator. Any help would be greatly appreciated

 

A car needs a lot more juice to crank an engine over then it then it needs to fire a plug. Your battery may have been push over the edge by all the cranking you did to try to figure out what is wrong but I doubt it is the cause of the problem. It can be pretty common to have to replace and battery or a starter right after a fuel pump/ignition failure.

Are you still losing spark before it dies? Now that you have spark have you check fuel pressure?

One mistake amateurs make is they tend to assume that if something is newer it cannot be at fault. When I did warrant work for GM most of the parts I replaced were less then a year old. We even had cars die backing off the transport truck. Most of us techs would keep known good parts to test problems. If you are testing for a bad ICM with a new defective ICM then it can drive you crazy trying to figure things out.

 

You might want to get that new alternator tested, my '93 Z28 acted like that when the alternator was going bad. I've seen and had "new" (most are rebuilt) alternators fail more than once or twice. That battery being dead could also be the problem, you might just need a battery. The alternator might not make enough power at low engine speed to keep it running especially if it's weak. Could be you need both a battery and alternator. If it was me I'd pull the battery and have it tested and if bad replace it, then get the alternator tested even if the car starts and runs with a fresh battery. If it's weak,well you said it's new so it should be under warranty so get another one.

 

yep electronic ignition will not work once voltage get so low. alternator will not work with a battery that is completely dead, has to have enough volts to operate.