So i've been having troubles recently(as in last year) my car wouldnt start, it would turn over but never actually fire, and every time i thought i found the problem, and thought it was fixed, it would keep dying and/or not starting later on. So i guess first of all if anyone has any suggestions on that i'd be glad to hear it. Started off friend told me the vats would possibly be bad, so i disabled that using EFI Live, and it worked for a week, then it didnt wanna start later, so then it seemed my battery was low and seemed it wasnt holding a charge, so i got a new battery, great it was fixed.....for a week again, so then it started throwing a code that the o2 sensors were bad, so i got new front o2 sensors(rear were removed with efilive). It also seemed to fix it, it ran great for 3 weeks this time, but eventually died after i got a car wash from the dealer(free), so we had it towed to the dealer and had them look at it, he said that the fuel pressure was great, the guy cleared the codes using his program and said it runs fine but this type of thing tends to happen when cars are "chipped"(i had mine dyno tuned through local shop). So it seemed to run fine for longer yet, infact i thought it was fixed, then later on my dad went to move it from the garage and it doesnt want to start again. Anyways, i'd like suggestions for what to do and what to diagnose next, also if you think it's a bad pcm i also have a question for that.

If it's a bad pcm then will i have to register a new vin with my EFI Live? or will it stay the same?

 

I had similar issues with VATS and had to replace the BCM in my Z28 due to poorly grounded nitrous wiring....doh.

This cured it for me, it got real old wondering whether or not the car was going to start every morning....

 

I doubt the pcm it'self is bad. The key resistor id ckt in the steering column could be going bad. Turning off vats will not correct this. It will disable the security light on the dash from coming on, hiding the problem.

When you have these no start conditions will it try to turn over but just not catch? Or will it just "click?"

The "tell" on the key id ckt going bad is if you have a no start failure and wait 3 mins and then get a start. Eventually the intermittent condition will become permanant. I've seen lots of these tumber key id ckt failures lately on Fbodies as they are getting longer in the tooth now.

You can pull the steering column and R/R the ckt or bypass it with an identical set of resistors matching the value of the key at the bcm.

Can you elaborate more on what is happening with the no start?

 

i think i stated this earlier, it is turning over but will not catch, it is not clicking(as if the battery were dead)

 

if you know of a link with writeup of how to bypass that would be awesome, otherwise more info and comments/questions/answers would be great.

 

I'm having the exact same problem. My car has been tuned. I had VATS problems, and bypassed it. Now it won't start at all. It just clicks like the battery is dead. Tried switching out the starter, tried jumping it, nothing!! Anybody have suggestions. I'm frustrated as hell!!

 

First check to see if you have injector power,pulse on start up, a local part store might have noid lights or even injector pulse testers.if you dont have inj. pulses on start up its most likely vats. To bypass;
@ the bottom of the steering collum their is a group of 3 very small wires, might be in a ORANGE NOT YELLOW coating. Inside will be three wires, I think they are orange, yellow, and black. If you want to bypass,first you need to measure the resistance of the resistor of the chip in your key, than get a resistor to match that. Get the wires ready by stripping a 1/2 inch insulation on the black, than cut the yellow and use the car side (not the key side) of the wire to the resistor and the other side of the resistor to black. this is inside info and if the wires inside the orange coating arent these colors STOP and re poast and ill check my shop key!!