1997 Chevy Blazer hard to start when cold and killed 3 new batteries

I have a 1997 Chevy Blazer, 2 door, 4.3 liter, v6. I have had a hard start when cold problem on-going for 3 years, and there is also some mysterious drain on the battery. It has killed 3 brand new batteries (took about a year to kill each battery). Currently I have a brand new Bosh battery. Currently there is no "service engine soon" light nor "check engine" light. It has recently had a complete tune up. New spark plugs, new distributor cap, new rotor, new fuel filter, and gets regular oil changes. Currently the battery gage is reading correct at 13.5 volts.

Some additional history about this 1997 Blazer - About 2 years ago I replaced the ignition switch, so I highly doubt it would be that. About 6 months ago I got a "service engine soon" light and it would not pass California smog check. I confirmed with 3 mechanics that it needed new fuel injectors. So I had the entire spider injector system replaced. The "service engine soon" light went out, it passed smog check, and it's been running fine since, BUT it still has the same exact hard start when cold issue, AND still drains the battery. Brand new battery #3 was just put in a week ago. The starter suddenly began making a grinding noise when starting, so I had the starter replaced with a brand new high quality starter - no more grinding noise. But still having the hard to start when cold, but it DOES start up after 2 or 3 tries. After I've been driving around for 10 minutes, park, I go into a store for 30 minutes or so, I come back out and it starts up immediately. So the problem with starting is usually just the first time I start it (or if it's been sitting for a while). I'd like to fix this mysterious slow drain on the battery that happens over the course of a year, because it has now killed 3 batteries in the past 3 years. From reading Chevy Blazer posts online about these types of problems, I'm guessing it could be any one (or several) of the following parts:

- Alternator ?
- a Relay ?
- a Fuse ?
- Ignition module ?
- Fuel pump ?
- Vacuum leak ?

What do you think is causing this hard start when cold issue? And what might be causing this very slow drain on the battery over the course of a year? Do these 2 problems seem related or do you think they are most likely 2 completely separate issues?

Start by checking fuel pressure on cold start, key on no crank. Get an inductive type ammeter, look for no more than about 1/2 amp draw after about a 15 min. shut down, this allows the modules to go to sleep.

Thanks for the info! I have not yet purchased an inductive type ammeter ... but here's some more symptoms over the past 24 hours. Last night at 3:30 AM it was cold out (46 degrees) and I needed to move my 1997 Chevy Blazer for street cleaning. I went out to move it to another street and it took 3 times to start, it also seemed like it wanted to stall once briefly during the short 1 block trip to move it to another parking space. But it did not stall out, just sort of felt like it was going to (briefly) and there were no warning lights on the dashboard. The battery gauge read 13.5 volts. I have just purchased a brand new AC Delco alternator, but it's sitting in the box, have not installed it yet.

The next afternoon, 12 hours later during the day, at about 3:30 PM the sun was shinning and the weather was a bit warmer (65 degrees). I went to retrieve my Blazer and it started right up on the first try. I drove around to several stores over the course of a couple of hours and it ran great the entire time, and started right up on the first try every time. This starting problem seems to only happen at night when the weather is cold, or in the morning when the weather is cold. What does this mean? Also could this starting problem have anything to do with dampness since there is quite a bit of condensation (dew) on everything in the very late-night or early morning hours?

You may want to scan it cold and look at the coolant temp sensor readings.