I'm working on this '96 LT-1 auto trans. I was told it was a no start and I'm starting from square one.
First, it has been sitting for 3 years and the battery was shot, gas is all varnished.
I replaced the battery and have done the folllowing checks and troubleshot the following:

1. Measured the resistance in the key resistor (7.44-7.49)
2. verified that value by finding the two pin connector under the dash from the lockswitch. Removed the key and had 0, inserted key and had measured value from earlier
3. Verified all fuses on passenger side panel as well as all maxi fuses on both locations by battery were good.
4. engine turns over and cranks fine, all dash instrument panel function correctly
5. engine will fire (roughly) after squirting throttle body cleaner into throttle body.
6. 12vdc signal from fuel pump relay verified at fuel pump connector under fuel door for 2 secs without cranking, solid 12vdc while cranking.

This leads me to understand that the VATS is not the issue since the ignition would be disabled if there were a problem and that the fuel pump would also be disabled.
I'm thinking that the fuel pump itself is shot...anyone have any input on this? I don't want to do any dart-board troubleshooting with this and only replace what is truly wrong, not what could be wrong.
Thanks in advance all,
Rob

 

I bought a 95 that had been setting about the same amount of time. The body control module needed a repair to get it to crank. The fuel system also was in a bad way. I did a new fuel pump, filter, regulator and injectors. Also a cap, rotor, wires and plugs. The fuel system had suffered the effects of gasahol, and the tune up was over due. It runs like new now.

 

Since it fires briefly, you know the spark is good.

Did you empty the old fuel and replace with new? If not, you need to. Also replace the fuel filter (passenger side, on the frame rail, but the cat). Once the fuel R&R is complete, turn the key to "run" a few times to pressurize the fuel rail. Put a gauge on the shrader valve at the back of the intake manifold. What is the pressure? Should be around 43psi and hold steady. Over the course of 30-45 minutes it will bleed down.

If you don't have pressure, then it's likely the fuel pump since you have power to the pump. Can you hear the pump run for 2 seconds when you turn the key to run? You should be able to hear it.

If you have pressure at the fuel rail, then you need to check the injectors. On an LT1, each should be ~12 ohms. Less than 10 or more than 17 means the injector coil for that injector is bad. Assuming they ohm check good, put a noid light on each injector and look for it to pulse during cranking. If there is no pulse, you may have a PCM issue. If the light does pulse, then it's likely the injectors are clogged shut with old fuel and need to be professionally cleaned or replaced.

 

I haven't drained the old fuel yet, but I will..(3/4 tank....groan) swapping the fuel filter is def on the list to as well. There is no fuel pressure at all...I have no fuel at the schrader valve.
I'll check the resistance for grins on the injectors and I'll get a noid light to do the pulse test as well.
It's sad that this car is in this state...28k miles.

 

Try checking the engine codes. That will help. Ground wires may be corroded. check connections on coil and module, use some dielectric grease on the connections, plug wires and ground connections also. Check fuel pressure and get fresh gas. Since it doesn't start you will need some one to turn key on and off to see if fuel pressure builds up. Should be around 43.5 psi.

 

Checking the codes came up with nothing...came back clean. I've checked for corrosion on connections under the hood everywhere I saw and came back clean. All fuses are good and clean. Battery terminals are clean and tight as well. I'm going to drain the all the gas and replace with fresh and some seafoam additive. Replace the fuel fiter and fuel pump as well if I don't get any other good clues as to what might be wrong. I've spoken to two other ASE cert mechanics I know and they are leaning towards a fuel pump as I am. 3 yr old gas can certainly jam up a fuel pump.

 

If you have power to the pump and the pump doesn't run as evidenced by no fuel pressure, I'd say the answer is pretty obvious. The horse is dead. Put a new pump in it.

 

It's been a while since I've been online here, so just for closure, it was the fuel pump that was the culprit..pressurized the lines and fired up second crank. Thanks all who helped out!

 

Got a new horse.

Hi-HO Silver and awayyyyy.

Glad to hear it runs again.