I just got my 88 blazer out of the shop because my stock computer chip wasn't working well with the new vortec heads. The guy put in a hypertec thermomaster chip and said that it was much better. Well, I drive home and everything is fine and dandy. Then when I try to start it up again after sitting for about an hour, it dies after about 5 secs. I keep restarting it until finally it runs. Then I put it in reverse and the minute I let off the gas to switch back into drive, it dies again. After a while it finally stays. One thing I noticed while it was running was that the voltmeter needle kept swaying between 13 volts and 17 volts and never stayed constant. Also, I have the timing advanced about 4 degrees for the vortec heads. Also, I've got a 180 thermostat in there right now and hypertec recommends a 160. So could a bad alternator make a tbi motor run bad? or is it the timing or the thermostat? I'll run to autozone and pick up a 160 thermostat and bring the alternator in to have it tested. Thanks for the help.