Why does my vehicle sometimes struggle to start?

I bought a used 2001 Ford Escape in August 2007 -- it presently has just under 75,000 miles. Until a couple weeks ago, every time I tried to start it, it would fire right up as one would expect. About 2 weeks ago, I came out after work and tried to start it -- you could hear the engine trying to start (weakly) but something wasn't right. I waited a few seconds and tried again… Same results. After about the 5th or 6th try, finally the engine weakly began working and then it became strong to how it normally sounds. I turned the vehicle off and tried to start it -- worked as expected. I've driven it since then with no issues… Until last night. Again, the same scenario where you can hear the engine trying to start, but not firing. After a few tries it starts it finally starts weakly and then sounds normal -- I can't get the symptom to reproduce on demand.

I live in Minnesota (it gets cold here!) so I replaced my battery this summer -- I don't think this is a battery issue as the starter sounds like it is trying to start when I turn the key.

Unfortunately, I'm a computer/electronics guy -- I don't know much about vehicles. Your insight would be greatly appreciated.

I bought a used 2001 Ford Escape in August 2007 -- it presently has just under 75,000 miles. Until a couple weeks ago, every time I tried to start it, it would fire right up as one would expect. About 2 weeks ago, I came out after work and tried to start it -- you could hear the engine trying to start (weakly) but something wasn't right. I waited a few seconds and tried again… Same results. After about the 5th or 6th try, finally the engine weakly began working and then it became strong to how it normally sounds. I turned the vehicle off and tried to start it -- worked as expected. I've driven it since then with no issues… Until last night. Again, the same scenario where you can hear the engine trying to start, but not firing. After a few tries it starts it finally starts weakly and then sounds normal -- I can't get the symptom to reproduce on demand.

I live in Minnesota (it gets cold here!) so I replaced my battery this summer -- I don't think this is a battery issue as the starter sounds like it is trying to start when I turn the key.

Unfortunately, I'm a computer/electronics guy -- I don't know much about vehicles. Your insight would be greatly appreciated.

Thanks!

Mike Assuming that you want to fix your car by doing yourself, the first thing you should do is to buy an after market repair manual for your car. You can get them at any auto repair store. They are model and year specific e.g. Ford Escape 2001-2006. The years vary according to model changes. Mine have trouble shooting sections that walk you through to systematically eliminate potential problems. In your case, the trouble shooting guide is essential. Your problems could be the battery, dirty cable connections, the starter, etc. 9 times out of 10, if you follow the trouble shooting guide, you should be able to find the problem. Get the battery checked out.
Sometimes even new batteries fail to hold much of a charge and have a fault with them.
Most new batteries come with at least a years guarantee and often a lot longer.
Make sure the terminals are clean as that can inhibit the charging process.
I'm only guessing at your problem though. Start with a Battery Test,… Sounds like a weak battery The battery could now be 15 years old, time to get it checked Time for a battery

Get the battery checked out.
Sometimes even new batteries fail to hold much of a charge and have a fault with them.
Most new batteries come with at least a years guarantee and often a lot longer.
Make sure the terminals are clean as that can inhibit the charging process.
I'm only guessing at your problem though.

Start with a Battery Test,… Sounds like a weak battery

The battery could now be 15 years old, time to get it checked

Time for a battery