95' Jetta Problems

I have 95' jetta celebration edition. It is a 5 speed andhas 160k miles. One day shut it off and tried to start it no more than 5min. later and it just turned over and would not do anything. I have another post on here and many thought it was the timing belt but it wasnt. It is at a mechanic now and they cant seem to figure it out either. They said it has spark, fuel injuctor pulse, ignition pulse, and everything it needs to run. They took out the alarm(after market,(in thecar when I bought it)because they said that it was spliced into other wires and it was a huge mess. The mechanic was surprised that it didnt catch the whole car on fire. He said that it could be shortin out the ignition system and not alowing it to start. Well today he did everything to it to try to get it to run but had no luck. He replaced the crank sensor(he said it didnt look so good)and he still cant get it to do anything. He said he was trying to run it off propane(doesnt sound right but hes the mechanic) and also try to hook it up to his own fuel system by bypassing to fuel pump. He talked to a vw technician all day and hasnt figured much out. If anyone has any ideas on what could possibly be wrong please help me the car has been at the mechanic for long enough and i dont have the money for them to be pickin at straws and just replacing stuff tryin to figure it out. Please help me.

Have they checked the fuel pressure or the engine computer for diagnostic codes?

Did they check the starter good. When you say you turn it over and nothing happens, does the starter crank? If not starter could be dead. Even if starter cranks it may need to be replaced. The gear on the starter kicks out when you turn the key and engages flywheel, then retracts, it could be messed up and not engaging flywheel and you could sit and crank starter all day. Or flywheel teeth could be worn down so bad starter gear can't turn them. Should take a few minutes to check if they have it up on lift, might be worth the time if the haven't checked it yet.

Check the ECM or the ECM relay. A good resource for do it yourself repairs is www.alldata.diy.com. Chilton Manuals are useless, Alldata makes software and repair manuals for proffesional garages. Alldata can tell you how to check the ECM and every thing and with just a multimeter!