Pontiac Repair: No Start 1993 Pontiac Grand Prix, pontiac grand prix, pontiac dealership

Question
I have a 1993 Pontiac Grand Prix 3.1. And for the last five months we have done so much work to it and still have not fixed our problem.We have had the car at a Pontiac dealership for a starting problem. The car only would start when it was warm outside. On the way to the Dealership it stalled 3 times wich was the first time it stalled while driving. Then when we got there it started just fine so we left it overnight, The  next day they said they had a hard time starting it they put it on the computer and said it does not have fuel injector pulses but has good spark and good fuel pressure.That is all they could tell me for 100.00 and they wanted 75.00 an hour to explore more, we were moving out of town that week so we decided to just tow the car with us.Since then we have replaced the O2 sensor, map sensor, battery, spark plugs and wires, fuel pump and a number of other things. The only major things we have not replaced is the 6 fuel injectors and the ECM. There is no check engine light and the car has black exhaust when it does start, but it will not stay running. And the timming chain is fine. Should we take it in again or can you help?  

Answer
Well first of all, the dealer told you where the problem area was and you didn't want to spend another $75 for them to pinpoint the problem. So then you spent a bunch more money to guess what the problem was and you still haven't fixed it. Remember this....diagnosis is cheaper than guessing.
From the symptom that you described and what the dealer found, I would have to say that you have an ignition module that is failing, but it also could be the ECM. The module would be what I would be looking at first.
Hope this helps you and if you have any more questions ,feel free to ask.