1999 jetta stops and wont start for 20 minutes what is causing it when it shuts down I get fuel but no spark I already changed ignition coil?

see if u can check for faulty codes that's means on dash board have it to show check engine light if so have some local shop get the codes for u if not try one thing at the time, most popular crank shaft sensor located in front of the engine right below of oil cooler,next cam shaft sensor or module there is inside of distribuitor, for that one u will need a the repair book if u are not familiar with those system,next speed control sensor one of the most common is located on rear of the trans. rigth below the battery,and the last cold start valve or coolant sent sensor the shippest way try used from pik up part u will spend just small amount on the parts but is 80% chance u will get that fix for 100's less good luck.....