ECM reset on battery disconnect and vaccum line question

[Jay Beezy]

I had a blown head gasket on my '92 Lumina and had to break the engine down. I got the heads shaved a little bit and got new gaskets and everything. I'll be through with putting the engine together Monday. and I want to fire it up to see if anything is wrong. However, I was told that when the gasket blew, the engine got so hot that the ECM had some kind of code so that the engine won't restart.
I'm trying to find out if the ECM will reset itself since I disconnected the battery while taking down the engine or will I have to get someone to to reset the ECM before the engine will start. Does the ECM reset if the battery is disconnected?
Also, there were several vaccum lines that were broken while we were breaking the engine down. I know the lines are important but should we fix those before we try to start the engine or could it be started and tested with the lines still broke?

[legendrd]

The ECM should reset after about 20 seconds of loss of power, at least it did on my 94 lumina 3.1, another way to reset the ecm is by pulling the fuse under the hood marked ecm and replacing it after about 20 seconds, you will then have to let the ecm re-learn how to idle, by starting the engine (DO NOT TOUCH THE GAS) put your foot on the brake and hold it in gear for about 10 mins, switch it off, wait 20 seconds, start it again and leave it idling in park.

[JERKY420]

that would be a good way to waist your time

all you have to do is disconnect the battery for 10 seconds not a fuse so there is no power to anything in your car then start your car with everything off including radio heater etc... for ten minutes don"t put it in gear shut the car off and then restart it with everything on and let it run for about ten minutes then your ecm is reset and that would be the absolutely correct way to reset everything in you ecm. but beyond all that your car should restart anyway after you finish putting it back together mine did and I did a complete engine swap.