vw jetta doesn't start smooth with warm engine only

Could you please give me advice?I have a problem with my '96 VW Jetta Gl (4cyl,2.0 manual). Just a couple of weeks ago I had a complete tune-up and timing belt change done on my car. Since then I experienced a problem that happens more often now. In the morning it starts without a problem no matter how bad the weather is. Then after driving it for a while and I turn it off, its almost impossible to turn it back on without letting it rest for a longer time. The engine cranks but its cranking for a long time before fires up and even when it does fire up it has almost no power.I have to push the gas for it to "wake up" so it won't just stop after starting. If I let it rest for a while then its easier to start it but when it starts the rpm shoots up like I started to car with my foot left on the gas, up to like 3000rpm. When I start it in the morning after a long night of rest then I have absolutely no problem with it. I feel like it has to do something with the recent tune up, maybe the ignition timing is retarded.
Thank you very much

If the shop wasn't familiar with VW's they may have not gotten all the timing marks correctly lined up. I would especially suspect this if the problem started immediately after the belt was replaced.

If the shop wasn't familiar with VW's they may have not gotten all the timing marks correctly lined up. I would especially suspect this if the problem started immediately after the belt was replaced.

Thank you so much for your reply boschman. I'm so confused when the problem started: after the tune-up or the belt. But im sure you were right and it happened after the belt, it made sense. I don't think the shop will take responsibility after a couple of weeks though:(. Would they have to redo their job completely? Do you think that this problem will cause more problems with ie.: starter in a long run? I won't be able to get it fixed for like 2 months because i have no money and im so worried that by the time i do have it ill have other problems.
Im sorry for bothering you,thank you

They only have to remove the upper belt cover & distributor cap to see the cam sprocket & distributor marks. It's probably something you can check yourself if you want to try.

Great! Thank you. Ill try to do it on my own but ill still try to ask the shop to take responsibility. Ill post my experiences when I get a chance to talk to them.

I would just check the marks, if they're off let the shop fix it. Do you have a manual or diagrams of what you're looking for?

I just talked to the shop and told them about the marks and they take 100% responsibility for their mistake. They will check & fix the problem for free so I don't have to worry anymore. If the problem has nothing to do with the marks then I will post that so everyone can get a chance to read it in case they have a similar problem.
Thank you!