can someone give me a idea

[drayrunner]

My 02 malibu with the rsm kit has a radom missfire, i been chasing for the last few weeks, checked everything i could think of, changed injectors, had it on a good snap on scanner didn;t show anything, it would missfire one cylinder all cylinders and some time run normal for a while, new plugs, wires checked the coils,module everything i could think of, until i took the plug of the coolant sensor, ran perfect no misses. i installed a new sensor pluged it in and i got the missfires, unpluged it runs good. never heard of that, anyway what should i look for. i got a monday appointment the dealer, so if somebody got a idea let me know, maybe i can save some money, the last thing i wanted to do was go to the dealer, but i;m stumped. thanks

[robertisaar]

so it doesn't miss when the ECT is unplugged?

i'd check the ECT to see if its bad....

[fbody_mike]

I had a similar problem with my 99 Lumina with a 3100. I would randomly get a random misfire. It would come and go at will, and I changed the normal things, like plugs and wires, but it still would come back. I even changed the "computer", but the problem only went away when I swapped out the module coil pack assembly. There was something wrong with the module in my case, and it was not heat releated because the problem would happen on first start at times. I also heard that it is best to treat the module and coils as a unit and change the whole thing at the same time.