I have a 95 z28 that was just freshly rebuilt. It's had a problem since I got it back around Christmas. I'm on my second new battery (the first had a dead cell). After I installed the new battery it ran fine and I didn't drive it the next day. The day after that I go to start it and its stone cold dead. I charge it and it turns over no problem. I remove the positive cable and it keeps running. Then I turn it off and back on and it just starts and dies. If I hold the key I can get it to stay on but the voltmeter keeps jumping around and then it will die. I've replaced the starter, ignition cylinder, alternator, opti, plugs, and most everything under the hood. Also the template keys that came with the cylinder work despite not having a chip? One of the wires on my old ignition was cut and my security light has been on since I bought it in 2011. Idk if any of that is relevant, just being thorough. I've spent every penny I have on this rebuild. I've been without a car for a year.

 

If a component of the PASS-Key system fails while the engine is running, the "SECURITY" light comes on full time, and the security system is bypassed. The engine will start without the proper resistor. Alternatively, someone could have inserted a resistor in the circuit to bypass that part of the system.

Here's a guide to the security system (courtesy of Shoebox - bookmark his site):

4th Gen LT1 F-Body Tech-PassKey/VATS

http://shbox.com/1/vats_bypass.jpg

With the system bypassed, it isn't likely that is the problem causing it to stall, but it would be a good idea to try and troubleshoot the security system to straighten it out.

Sounds like you may have some sort of parasitic load draining the battery when the key is off. That can be traced by putting a mult-meter set to DC amps in series with the battery cable, with the key in the off position (DO NOT TRY AND START THE ENGINE - you will toast the multi-meter). Any current flow more than a few 1/10ths of an amp will need to be tracked down.

The stalling is probably not related to the battery running down overnight. Possible reasons for the stall:

-weak fuel pressure (check pressure)
-EGR valve stuck open
-faulty MAF sensor (unplug MAF sensor, putting PCM into speed-density
-faulty coolant temp sensor in water pump housing (see test procedure below)

4th Gen LT1 F-body Tech Articles

Need to check it for codes.

https://www.camaroz28.com/forums/com...95-lt1-874306/

 

I forgot to mention that the coolant temp sensor isn't hooked up, because they gave me the wrong one (on block) and when it was running it smelled heavily of exhaust in the cab.

 

Which sensor is not hooked up, the one on the front of the water pump or the one in the driver side head? There is none in the block. The one in the head only affects the gauge.

 

That's what I meant, in the head.