[Bratty]

Hello Everybody,
I'm in need of some advice & help. I have a Pontiac Bonneville with a 3.8 and year is 1990. Out of no where the car would not start, just would crank. Finally took it to the shop. They went and put on a new Module or Modulator the plate right under and connected to the coil pack, then a new coil pack and then a cam sensor. & also checked fuel pressure. After several hundred dollars out of my pocket guess what I still have the same problem. Got home barely, as it shut off, and luckily got it to start after cooling enough to pull in my drive way. Car will start when it is cooled down. After about 5 to 10 minutes of running it sputters and shuts off then it will not start again until it has had a long time to cool off. You would think it has bad gas by actions but isn't the case.
Today we checked the fire from the spark plugs. When cranking there is no spark from any of the plugs and this was checked when the car does not start.
I have called around and someone mentioned possibly a Crank Shaft Sensor. My question is does anyone think that sensor is my problem??? I cannot afford to run it back into a shop plus the cost of having it towed back to a mechanic ughhh. Also for this car where is this sensor located? The guys at the auto parts place said down the back side of motor. I saw a sensor that looks to be going to exhaust and tons of other plugs down there lol. They said some times they will get cracked or damaged and would cause the problem I'm having and if I could pull it out might could see that. I would highly appreciate any advice on this. The mechanics have already drove me broke. Also if we put this sensor on and it does not solve the problem what else could it possibly be?