96 jetta wont start, we changed the alternator, battery, and the ecu computer. Everything works the only way i can start it is by jumping the alternator. when i turn the car off the emergency lights turn on and stays on, same as the radio. Any ideas or suggestions will be greatly appreciated.

SOURCE: replaced distributor in 95 jetta, now it won't start

Go back to bacic timing. put your crack shaft pully on 0 degree. Take the timing belt cover off and make sure that with the crank shaft pully is on o degree the cam shaft pully is align with a mark it has at 12:oo o'clock. If not so, turn the engine one more time using a 12 point 19mm sucket on the crank shaft till you get to 0 again. Do it very slow, it's very presice. when you align those two marks, then take the distribuitors cap off. Rotor should be pointing at cylinder 1 exactly on it. There is mark on the body of ignition to confirm this. Hope this does it. Also check if your cables are mixed up.

SOURCE: 2006 jetta tdi radio not working after jump start

battery is dead... have the battery and alternator tested for functionality

SOURCE: 96 jetta treck wont start ( radio written SAVE )

I will work with some assumptions here.Your radio has a hole in each corner of it.Use nails and insert into the holes.GENTLY pull radio out and there should be a sticker on the body of the radio with a 4 number code.Write it down and put the radio back into the dash.Hold the scan and mode button in at the same time and the word SAFE will go away.Now,your station preset buttons are the keyboard.Push the #1 preset repeatedly until the first number in your code is displayed.then on to 2 for the 2nd and so on.After you put in your 4 number code,hold in scan and mode again and in about 2 seconds,tunes!!!!!You might get lucky and call your local vw dealer with the VIN of your car.They might have your code on file.Will save you a lot of trouble as the radio is not easy to remove.
best of luck!!!

SOURCE: 2002 Volkswagon Jetta won't start in cold weather

I had a similar problem with my older 2000 model jetta 1,9TDi and also with my current 2002 1,9TDI.
On both cars the problem started once the cars got past approx.160th KM.
Take the car to any Bosch diesel dealer and ask them to increase the dwell time on the glow plugs (increase the time that the glow plugs stay on, when the ignition is swtiched on)
Cheers.

SOURCE: 96 vw jetta 2.0l will turn over but will not start

I had a problem like this on a 1997 VW Jetta 2.0L. I suggest you obtain a multimeter, a gas pressure gauge, and a used injector from a junk yard. You need to find if the car has spark if it is getting gas and if the injector is firing. Plug a used spark plug into say # 4 spark plug wire and ground end against the manifold or other ground. Have someone crank the engine and see if there is spark. If there is spark then disconnect the electrical connector and plug in the used injector and hold in your hand. Have someone crank the engine and if it clicks as the engine revolves the injector is firing. Now if you have spark and an injector that clicks then put the pressure gauge in the upper line going to the injector manifold. Use a T so that the fuel can still flow into the manifold. If these three things check out. You need to also verify the engine is timed correctly and the timing belt did not slip a few teeth. I had a problem with my crankshaft sensor. I bought a new one and although I was getting about a .3 volt ac signal, I still had no spark at spark plugs. I wound up getting another new crankshaft sensor and read 3 volts ac from the new sensor. I then had good spark Hope this helps