I know this is a massive wall of text but I’m trying to not leave any details out because I am well aware how much of a pain diagnosing a car can be, so please bear with me.
I drive a '01 Honda Civic lx automatic with 170k miles.
About a week ago my car was having a difficult time starting, and I had to hold the key longer and longer to get it to turn over. Initially I thought it was my alternator/battery so I went and had them both tested. At first it said my alternator was fine but with some prompting I got the guy to test just the battery and it said the battery was bad, which he said was weird because if the battery was bad then his device should have said the alternator was bad too and the only way to really tell was to go get a new battery and then come back and test it. So I went and replaced the battery and it seemed fine at first so I didn’t rush back to test my alternator. The next morning it started to do it again but pretty sporadically. Sometimes it would take a couple seconds to turn over and other times it will start up immediately with no problems or what felt like it stuttering.
Unfortunately, today while driving, my car lost acceleration for maybe a second and then regained acceleration. Then about 30 seconds later it lost it again but regained it a second or two later. It did this 3 times in the span of maybe 3 minutes. Luckily, I was really close to home so I was able to safely park it in the driveway and not get stranded somewhere.
My car never revved up during any of these failures, like it did when my tranny failed (I got that replaced last year) and the rpm needle would start to drop. I also didn’t notice my radio dim or lose power (the radio was on at the time). However, this morning my cigarette lighter did stop working.
My check engine light did go on, but I got it coded and it says it’s my gas cap. I initially thought that the light was on because maybe I forgot to turn the cap all the way when I last filled up because it on about a quarter of tank in but with my car acting the way it is, I’m not so sure now. I know you’re probably thinking ‘well duh, you’re check engine light is on dummy!’ but this has been happening way before the light came on and in the past I did forget to fully twist my cap and that caused the same code and when I retightened it the light went off on its own about half a tank later, so I’m not sure if that’s really linked to the problem.
I have had my distributor go out on me in my '96 honda civic and these ‘stutters’ kind of felt like that except with my last honda there was no warning like this and it never regained acceleration.
Any help would be appreciated, I’m not a mechanic and I just don’t know what to focus on troubleshooting first.