Car Won't Start: Troubleshoot

[ivymike1031]

I thought that some of you might enjoy this, so I'm posting it.

The registration ran out on my girlfriend's car last saturday, and we couldn't re-register it until some paperwork showed up (problems with the IL DMV), so the car spent the weekend in the garage, except for a brief period on Sunday when I drove it out into the driveway to clear some space in the garage for some other projects I had going on (pulled back in a few hours later). Yesterday (Wednesday), we had the paperwork taken care of, and my girlfriend was ready to start driving the car. She reports that when she got in the car and tried to start it, the engine sounded normal for a second, then made a funny sound and started sounding really strange. I wasn't there while she was doing this, but I can confirm that when I got home, it sure sounded odd while cranking. The sound wasn't like it had absolutely no compression, but it also didn't sound like the starter was running against much resistance. The engine was clearly NOT in the mood to start.

The vehicle is a '97 Honda Civic dx, with 125,000 miles on it. The engine is a SOHC non-Vtec 1.6L D-series (D16Y8 if I'm not mistaken). It has been impeccably maintained, for the most part. I did succeed in getting the car to run again, and now it shows no signs that there ever was a problem. I'm not entirely certain (even now) of what the culprit was, but the one explanation that made sense to me was later confirmed as a common problem by a guy who has done engine development for 20 years, so I think we have a solid theory about what the trouble may have been. The point of this post is to allow y'all to take some stabs at it and see what you come up with. I did quite a lot of tests before I got the thing running, so if you'd want to check something in the course of diagnosing the problem, go ahead and suggest the check, and I'll give the closest thing that I have to the desired test results.

Beginning condition: the above information. Car doesn't start, and it sounds odd while cranking. Doesn't sound like it has no compression, but sounds like the starter isn't struggling much either. Car ran perfectly the last time it was started, which was 3 days earlier (no roughness in the idle, no hesitation on acceleration, no strange noises, etc...). The car has been garaged since the last time it ran. Temps in the garage have probably ranged from the high 50's to low 90's, with moderate humidity (I don't expect this to have a big bearing on your diagnosis).

Troubleshoot away....