You didn't give me much to go on here so I'll do my best to help you out. If the car won't start at all it could be something pretty serious like a broken timing belt or other internals broken.
If it will start but has very little power It could be a Catalytic convertor that will usually give off a rotten egg odor. It could be a clogged tail pipe. It could be a clogged fuel filter.
It could also be a bad fuel pump. To check this turn off the radio, get in roll the window down and close the door so the chimes aren't making noise. Turn the key to "on" (not start, just on) and listen for a soft growling sound at the gas tank. the growl should last three to five seconds. If there is no growling your fuel pump is not working. It could be bad or maybe it is not getting power. Two things will keep it from getting power. One is low oil pressure (so check your oil to make sure it is at the full line) or two, a bad fuse.
Sometimes a fuel pump just gets weak and needs to be replaced. I'd start with checking the oil and fuse to the pump. Next I'd replace the fuel filter. If you still have the problem it's time to get a mechanic you trust to look at it.
I would expect that the power for the fuel pump would be supplied through the ignition switch so I would start there, that is check the ignition switch. Also check the associated wiring for cuts or possibly a loose plug connection.
Low fuel pressure
I would suspect either a loose connection or a corroded battery terminal.
I would expect that the power for the fuel pump would be supplied through the ignition switch so I would start there, that is check the ignition switch.
If the Chevy Celebrity radiator is smaller that the Saturn radiator it might well overheat from not enough cooling capacity. If the Chevy Celebrity radiator is the same size or larger than the Saturn radiator I would think it would not over heat.
I have not seen a standard Chevy Celebrity with a toggle switch under the dash. I would suspect that is something a previous owner installed.
To answer your question I would need to know the year of your Celebrity as well as which one of the four transmissions it has.
I would think that on size alone it would fit and mount in. Depending on which of the engines the 1985 Celebrity had you might need to make a number of modifications to use the Corsica engine in the Celebrity. The two engines are NOT identical.
I would need to know the year and engine type to answer this question.
There is no way to post the detailed description plus illustrations that would help you do a brake job. I would suggest you consult either a Chilton manual or Haynes manual to help you do a successful brake job on your Chevy Celebrity.
TheChevy Celebrity engine wiring harness would not likely be available new from Chevrolet. The only likely source would be a wrecking yard and prices there vary widely from yard to yard.
most Chevy cps's are located in the timing cover(behind the balancer). I'm not certain on the Celebrity, but it would be a good place to check.AnswerOn my 1986 Celebrity 2.5, it is beneath the intake manifold on the back of the engine.