Oldsmobile/Buick Repair: 1991 bravada, hello carol, wire connections

Question
Van,
I have a 1991 bravada, with a new 4.3, has only 3,000 miles now. I'm having a problem with it starting. It will start fine for a few days, and then the next it won't. I have had it to 3 mechanics and they can not seem to find the problem, It has new everything almost. We know that it is not getting fire, as it will crank and continue to do so but will not start, all gauges work fine, and it runs great when it does start and run, but you never know when its not going too. If it does start and run then you can turn it off and it starts back up. For instance this week it started and ran fine until friday and it would not start and today it would not start either. We are about at the end of our rope. Any help would be greatly appreciated. P.S. you can pour gas right into the carb. and it still will not start.
Carol

Answer
Hello Carol,
Pouring the gas would normally be a good try at isolating the problem, but seems you have already isolated that there is no spark, so no matter how much you dump in, it won't start.
Sinse it has a NEW 4.3, I would take that to mean it was installed recently.
So the first thing I would check is all the wire connections.
Also check the wires near the connections for pinching or rubbing.
Then check for voltage at the ignition, coil, etc.
The ignition module can be tested at a parts store.
Don't just check for voltage at the ignition parts with the key in run. Voltage also needs to be there while cranking the engine. A bad ignition switch could cause a problem there.

Van