Volvo: 1991 240 w/LH-Jetronic Fuel Injection, not starting, air filter assembly, jetronic fuel injection

Question
It seems with the change in the temperature (air pressure, full moon, who knows) and my car will not start. The last time this happened I left it overnight and it started. Drove it home. Turned it off for about 10 minutes and when I went to start up again, problem is back. Had the car towed to a local shop (big mistake) and after 4 days they said "they got it started" and something about a problem with the vacuum. Yesterday the problem came back and refused to start. I left it alone over night and tried to start it early the next morning. Nothing. I checked what I know of for vacuum lines to see if anything was disconnected or punctured. The lines appear servicable. I don't own a pressure checker and working by myself I can't tell if anything besides the engine cranking is going on. I remmoved the hose to the air filter assembly and shot some starter fluid up into it. I took that starter fluid as if to start but it seems no gas was getting into the system.

What I would like is to at least get this started and drive it home, about 5 miles. Once at home I can take another look and try to actually fix it properly. I'm fairly handy but not much of a mechanic when it comes to diagnostics. I'm from the school of "spark and fuel". If it's getting juice then it's probably something with the fuel system sort of thing. Hey, my first car had a generator and only need a few tools to keep it going.

Is there any resource you could point me to that diagram the vacuum system for that car or could you explain what I should be looking at? FYI, last year and about 13K miles ago I had the MSA replaced.

Thanks for your time.  

Answer
Len,
Your might be over your head without the tools and test equipment. First thing to do is test the fuel pressure. Test for spark, and see if the injectors are getting a pulse. When the car is cranked over is power flowing to the main and pre pump? Fuel pump and pre pump fuse good? How about the wires off the battery? Is the fuel pump and injection relay in good condition? Could the timing belt have broken?
I really don't think that the vacuum line will cause a no start. Possibly the large vaccum hose to the brake booster or even the booster valve.