Pontiac Repair: 1995 Pontiac Grand Prix no start problem, crank shaft, manifold gaskets

Question
The problem, my car runs great first start of the day and I can drive for hours without a problem, but when I turn it off and try to start again 30 -60 minutes later it chuggles and dies and won't start for a least 3-5 hours later, then runs fine again.  It trys to turn over and the battery does not drag, no signs of a bad altenator. Three different auto repair garages tell me the following: either the cam shaft sensor, crank shaft sensor, or ignition sensor, bad & loose hoses, apparantly the last fix resulted in hand made manifold gaskets I did not know about and may also be causing contamination on my low coolant sensor cause it stays one, however back to the no start problem;  my engine is getting to much air also from the manifold non tight gaskets,&  bad and loose hoses and possibly the sensor's I mentioned.  So before I shove out money I don't have I am doing some homework and found your site.  What do you think is going on. Someone else said I do not have a crank shaft sensor. So I don't know whom to believe. Help

Answer
Hi Pam:
do you know which V6 engine is in this car? 3100 V6 or 3.4 dual over head cam V6?

My first though is a fuel delivery issue where the fule injectors are leaking into the engine when it's turned off or the fule pressure is bleeding off into the tank when you turn the key off and the result is a vapor lock or an extremly rich condition that is not allowing it to run. when it does start and run does it billow black smoke out the tail pipe?

Something sound fishey about "hand made anything"

In order to find the issue here it's going to have to be driven by someone untill hot and then sit and try to restart it and see what's missing in the puzzle as to why it will not start. Some of the suggestions given to you are not to far out in left field but they are all guesses just like mine. A cam sensor will not prevent either engine from starting but if that sensor is bad it will run bad and cause a service engine soon lamp to come on. A crank sensor and or ignition module are good guesses but unless someone verifies that the engine is missing spark when it will not start it's just a guess.

Good luck :0