I know this is a very popular issue by reading past posts. Is there a comprehensive list of all the possibilities of this problem? I'll start a list:

1) ICM@ $129.00
2) coil pack 3@ $24.99
3) fuel pump @$134.00
4) fuel relay @ $5.99
5) Fuel tank @ $157.00
6) Battery cables @ 36.00
7) Both grounds by drivers side and passengers side cleaned @ labor
fuel injectors: haven't tried yet
9) ECM: next on the list
10) ICM harness? any thoughts?
11) Key?
12) ??????

Car starts and runs really good and strong but when shut off won't start back up, no check engine light so not sure if I can get a code to come up. Any suggestions would be greatly appreciated.

Before you start replacing stuff you need to determine which system is not working. When the car wont start you need to check spark. If you have spark then concentrate on the fuel system. If no spark then you work on the electrical system. Check for spark and let us know.

Spark comes and goes. When it starts there is obviously spark when it doesn't there is none. The fuel items were replaced because of unsurity but the pump was the original (190k) and the tank was broken inside causing stalling when cornering at any speed then coming back to life (thanks to forum for fix). I forgot to add that the Cam sensor and crank sensor have also been replaced within the last year as this has been an ongoing problem for awhile now but is now at it'* worst.

Do you have a chipped key? Try cleaning the chip with some finger nail polish remover. Might help, and it can't hurt.

Thanks I have read that on a previous post, so I tried it but unfortunatly it didn't help. The reason my screen name is what it is, I have 3 92 Bonnevilles 1 SSEi and 2 SSE all white, Tan leather supercharged works fine (mine) Grey leather (wifes) has issue, tan cloth is parts(body) car. Going to down mine remove ECM and put in wifes car as next test.

If you have the parts on hand, then ya, swap them out and see if the problem goes away. Let us know what happens.

Crank sensor is not on your list

Thanks for the reply, actually the Crank sensor was on the third post right after the Cam sensor just forgot to make a capital C. Tried cleaning the key again and it started twice yesterday then wouldn't start last night. My Wife said it started 7 times today but when she sent out my son after school no start..arrrrrrrggggggggggggg! Swapped ECM from supercharged car to other and no difference to wifes car but supercharged starts just fine. Wasn't paying attention previously but when super starts and runs fine there is no security light on though it blinks when key is first inserted and after car is turned off. On the other hand when SSE non starts the security light is always on. The car is equipped with the system but have never had the remote so didn't think it was much of a problem. Is the key switch bad? I've read on other posts that this could be the case. Thoughts?

When you say no start you mean the engine does not crank or turn over? No engine rotation what so ever is that correct..because you are on the right track..my bonnie had that exact problem 3 mos ago and it was the key switch in the steering column with the same security light flashing and no start condition. The key switch is connected to long orange wire and that wire will corrode and snap over time resulting in a random no start condition untill it snaps completely then you get stranded. he installed a "jumper wire" ..he works for an auto alarm place and i have been good ever since. i will email him now for more details.. he says he sees this often on our 1992 bonevilles.

How to bypass the VATS system in a late model GM vehicle
heres a very good link info page on what you may possibly be dealin with. I know how darn aggravating it has been for you but don't give up you are very close to getting it resovled. This is exactly what i did and i have been running fine ever since..I hope this help my friend. best of luck.