Long story short, I replaced LOTS of parts..
LIM AND UIM, thermostat, hoses, plugs, wires etc.

Started car and it ran REALLY rough and choked out.

Realized the firing order was wrong, fixed the firing order.

Now when I turn the key I get ONE click noise from the engine bay
and the car wont start.... Not a fast clicking/ticking just ONE click.

Gauges light up, dash lights come on etc so there is power from the battery... just no starting.

Any ideas?

By the way, battery is tested GOOD and charged.

This is the 1996 Olds 88 in your profile, right?

With recent UIM/LIM work and this drastic of a change and good battery I'd say pull the plugs, turn it over, and see if a cylinder is full of coolant . . . ?

Maybe you should check for a spark at all 3 front cylinders.

Thanks guys, I will check both of those things.

I find it odd that it was running when the firing order was wrong though. And now that the order is right it won't start.

Maybe just coincidence?

Or the starter just happened to go at the same time. No real way to test the starter with out a volt meter though right?

Can test it with a test light.......attach it to a good ground.......touch the large bat cable at starter, should be as bright as when test light is attached across the battery terminals..... then touch the purple wire connector at the solenoid....should be bright when key is in the crank position.....

Instead of having to pull plugs, manually try to rotate the crank bolt......if you can rotate the engine manually, and the test light passes both tests, need a starter.....

Thanks, I also read that if I jump start the car with a set of heavy gauge wires and the car starts than the starter is most likely the problem. No?

UPDATE: Problem was only the battery cable being too loose. Go figure!