how to fix a daewoo nubira to start when i changed out the timing change and water pump on a 2002 ?
I 'm very puzzle and don’t know what else to do.
First…you need to go to a good independent mechanic to sort out your problem. Since you are an amateur…I suspect that your timing belt was installed out of time. You will damage your engine if you continue to try and start your vehicle. The damage may already have been done so go see that mechanic.
In the absence of any helpful information from the OP, I am going to do a WAG that the timing belt (?) was not installed correctly.
However, that is just a guess from afar.
You can help us to give better guesses by telling us exactly what is happening when the engine doesn’t start. You can also help us to help you by telling us whether you replaced the timing belt (?) proactively, or whether the old belt snapped.
Is the engine cranking when you turn the key, or do you only hear a clicking noise, or do you hear no noises at all?
If the engine is cranking…Is it cranking at the normal speed, or is it cranking faster than usual?
Have you verified whether there is compression in the cylinders?
Have you verified whether there is fuel going to the engine/
Is there spark?
Sorry, but it is a Daewoo Nubira. You’ve already spent more time than this POS is worth typing your question. 
+1 to VDC’s post.
Mustangman, be nice…
@redd, putting in a timing chain(?) requires careful attention to detail to get the camshaft and crankshaft synced. Then, any ignition timing sensors or distributors also need to be synced. Your brief post gives us very little information on how you did the work and what you’ve done so far to determine what is wrong.
@mustangman, down, boy, down!!
OK, OK, Sorry for that post. It is still worth something in parts to other Nubira owners and as scrap steel. 
It was also built by a defunct company, parts of which were absorbed into GM. And I thought it was getting difficult to find parts for my Saab! This car will be a nightmare.
I agree with @VDCdriver, some mistake in the timing belt install is likely preventing a restart. 180 degrees out? One or both cams? Hopefully this not an interference motor.
“Hopefully this not an interference motor.”
+1
And, it would be helpful if the OP responded to my questions, particularly, “You can also help us to help you by telling us whether you replaced the timing belt (?) proactively, or whether the old belt snapped.”
If it is an interference engine, and if the belt snapped, then it was probably not even worthwhile to replace the timing belt on a badly-damaged engine. Hopefully, it is not an interference engine and hopefully the belt was replaced proactively.
@redd–Are you still here?
How about responding to my questions?
@Mustangman…I can’t speak for Daewoo vehicles because I have never owned one or even worked on one. I own a Daewoo AR-15 for many years and it was more reliable than any other AR-15 I’ve ever fired. It was smooth operating and never jammed even after 1200 rounds or so. A friend of mine made a ridiculous offer for it and I sold it. I later found out that Daewoo designers replaced the direct gas system of the AR-15 with the more common and reliable gas piston system. That was the reason it was such a sweet shooting rifle. @redd…hello, hello.
@missileman, I had some experience with Daewoo when I worked for a parts supplier. The auto group of Daewoo was similar to Hyundai, the auto arm of a huge Korean company. Daewoo and Hyundai both had a reputation for building poor cars, Hyundai progressed, Daewoo went under. Both companies, however had divisions that did things VERY right. Hyundai, ships. Apparently Daewoo built really good arms but the parent company collapsed in the late 90’s.