Z28Twitch

Been banging my head against my car for a few days now. I'm the second owner and have worked on this thing since I bought it back in 2002. For the life of me, I cannot figure out what is going on. I had a kid a couple years back and the car has been sitting. So I push it out, new fluids, new battery, good once over, hit the key and she cranks with ease. Keep cranking, fires up, stumbled and chopped for a few seconds and died...then never did anything ever again. Turn the key forward and I get radio, hvac, headlights, dome lights, horn, and so on and so on, but no fuel pump prime and nothing when I go to start it. The voltage gauge reads at the lowest point and never moves either. I've checked connections at the battery, starter, and engine block...all check out with a volt meter. Probed the fusible links, all good. Power at both fuse boxes and all fuse locations. Put the battery from my Tahoe in with no change. (battery from car started truck with no issues at all). VATS was tuned out YEARS ago. Tried hot wiring it on the blue connector off the column, can get all accessories but no fuel pump and no starter. What else could it be?
Luckily I don't have to rely on this car for anything but fun so I can take my sweet time, still would like to give er a rip soon though...thanks.

Injuneer

Will the fuel pump run if you apply 12 volts to the prime connector?

Courtesy of Shoebox

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

That bypasses the PCM and the fuel pump relay.

Do you have an OBD-1 scanner, to see if it will connect w/ the PCM?

When the VATS was programmed out of the PCM, was the theft deterrent relay also bypassed?

The PCM gets ignition power from the ignition switch. The starter relay (TDR) gets power from the ignition switch. Possible ignition switch failure? Becoming fairly common, including burned and loose connection pins. See First paragraph in this switch R&R writeup:

4th Gen F-body Ignition Switch Replacement

Z28Twitch

I remember something about a yellow and black wire going to ground but I dont recall if I ever did it or not.
When I jumped the ignition switch connector it still didnt do anything. Im all set with pulling the column just to replace a unit thats lasted 24 years with something that will fail within 2. Does the shbox site have a diagram that I can use to rig up a kill switch/button start? Just seems more worth it to me to put the hours in for an "upgrade" instead of a repair hahaha.
I totally forgot about the prime wire. If I feed it 12v and the pump runs though, wont that just confirm my pump still works lol?
My laptop with tunercats has been M.I.A. for about 5 years so Ide have to buy something to look into the obd side of things.

Thanks

Injuneer

It will confirm the relay is dead, or the PCM is not supplying the 12 volt control signal to the relay, or the ignition switch is not providing 12 volts to the load side of the relay. We're trying to identify a possible PCM failure or an ignition switch failure.

Shoebox does not have a push button start diagram that I am aware of. But he has the fuel pump/PCM wiring diagram, and the ignition/starter diagram.

http://shbox.com/1/1995_pcm3.jpg

http://shbox.com/1/starter_charging_95.jpg

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