hairline crack in distributor part
 

I noticed a hairline crack in this part on the distributor of my '92 Accord (you can see it where I'm pointing in the photo): http://i207.photobucket.com/albums/b...ps53a55535.jpg I've been informed this part may be what is called the top dead center sensor (although I'm not sure if this is correct information; perhaps someone here could confirm that for me?). Also, I noticed my new rotor has a hairline crack in it too. It's a crack only within one of the "webs" of the plastic part, and it doesn't extend from or to any of the metal of the rotor, just within the plastic. Here's a photo of my old rotor, where I am pointing with the pen to the location of where the crack is on my new rotor (new rotor still on distributor). The photo is rather dark but still viewable: http://i207.photobucket.com/albums/b...ps70820934.jpg
I'd like an opinion as to whether it could be very likely either of these cracked parts could be preventing the car from starting (I get cranking but no start. It chugs once or twice like it might be ready to catch and start during cranking, but will not start). I checked spark from all plug wires with a spark tester, and get spark on all wires, but am not experienced enough to tell whether the spark is abnormal; seems kind of like an interrupted or perhaps weak sparking to me as I observe it while cranking. Any comment about this appreciated.

I doubt the sensor is causing problems unless it's electrically faulted (open/short) in sensing coil. It could be TDC, CPS, CYP sensor. I'm not sure which you're pointing to. You can download a shop manual from DIY forum, Online Manuals post and get resistance specs for the sensors to check.

Replace the rotor. It's too cheap to worry about. It might not be the problem, but not worth checking further.

Any recent work or problems? Did this stop while driving or just fail to start after stopping?

First step w/ all no-start conditions is to determine if spark or fuel is causing no-start. I like to start w/ turning keyswitch to ON and listening for fuel pump to come on (whirring noise from gas tank) and run for 2-3 secs. If you hear this every time, then fuel delivery is likely but does not totally rule out fuel.

Check for starting by spraying throttle body cleaner into air intake, a good 5-10 sec spray. If engine starts and runs briefly, spark is good and fuel delivery is somehow the problem. If no start persists, the spark is not adequate to run engine despite visual spark. Sometimes a weak spark will not be enough to ignite fuel or engine compression prevents spark from jumping across spark gap (higher air pressure increases resistance).

Try the above tests and report your findings. Someone can help.

good luck

The original issue was a good strong cranking but no start issue. This was a a few weeks back. So, then, suspecting a possible failed main relay, I removed mine and inspection revealed definite obvious cracks and general deterioration of several of the soldered contacts. I took the main relay to a guy who works on electronics and had him re-solder the contacts just as described here: MarkLamond.co.uk - PGM-Fi - Main Relay
After that, the car started right up, no problem, and I thought the problem was solved. However, a few days later, , the crank-but-no-start issue happened again. Upon inspection of the cap and rotor, I discovered the rotor edge contact had a charred area on it; here's a picture of it then: http://s207.photobucket.com/albums/s...psc5f2a38e.jpg
I had to order a new rotor, there was none for sale locally. Meanwhile I scraped off the charred area of the rotor with a fine file, back to bare metal, and tried starting with the cleaned-off rotor. Started right up, and worked fine. Again I thought the problem was solved. Then, when the new rotor arrived, I went ahead and installed it (along with a new cap too).
But since installing the new rotor, I'm back to the cranks but no-start issue again! Getting the old rotor off was a very hard pull with my fingers, it was on so tight. Likewise, putting the new rotor onto the shaft wasn't easy either; it didn't slip on without me having to push really really hard. In fact I could only get it halfway on before I decided maybe I should sand some of the rather rusty looking metal off the end of the shaft before trying to push it on all the way. So I pulled the new rotor back off, and even though it was only halfway on, it still was very tight on there, requiring me to pull especially hard to finally get it off. After sanding the the end of the shaft a little with some fine sandpaper I was able to slip the new rotor onto the shaft all the way, but still it seemed much harder to push onto the end of the shaft than it seemed it should be. Anyway, with all that struggling around with the rotor, I ended up with the crack in it as I described in my initial post here. I did check with the spark tester and I am getting spark from all four plug wires, but as I described. Seeing that I'm at least getting spark, now I moved on consider proper fuel delivery, and went ahead and changed out the fuel filter, thinking (hoping) that may be the only problem (fuel filter hadn't been changed for a long time). But new fuel filter made no difference. Still got exact same crank but no-start result as I've described. So far I haven't done anything further fuel-related troubleshooting.
I looked again at the distributor/rotor area and then happened to notice the hairline-looking crack running through that sensor part (what I'm pointing to in the photo in my initial post here). I'm hearing the appropriate clicks from the main relay when turning the key, and also hear the fuel pump kick in a few seconds, which should indicate the relay isn't the issue. With that crack in that sensor, I sort of am suspecting it may be bad and may causing the issue. Although I didn't accidentally crack it or even touch it myself; it must've happened by itself, no clue on how long it might have been like that. I'm thinking of trying to see if it'll throw a code; I would think if the sensor was bad it would throw a code? Wish I knew for sure which sensor it is. Any more comments/advice appreciated. Sorry for the long story here but just hoping with a little more background explained maybe it'll help others here to help me. Thanks!

You are still stuck w/ possible weak spark or fuel delivery issue. Try the starter fluid start test and see if it will catch/run briefly.

Do you have a timing light? If yes, check for spark by attaching inductive timing light lead to spark plug lead. Turn engine over and check for flashes w/ timing light. No flashes mean no spark in cylinder.

good luck

I haven't had a chance to do the starter fluid test yet, but will. And no, I don't have access to a timing light:(
I did try a check for codes. (I have OBD1 and used the paper clip method to jumper the service connector terminals and hen watched the check engine light for code blinks.) I seemed to get alternating trouble codes 15 and 16. I get one long blink followed by six short blinks, then I get one long blink followed by five short blinks; those two sequences over and over. The OBD1 trouble diagnostic code information I have says 15 means "ignition output signal", and 16 means "fuel injectors".
Does that make any sense? Comments please? Thanks again

15:
Check the wiring harness at the distributor. Look for loose/dirty/corroded connections. Ignition output signal is that circuit where the ECM tells the ignitor to fire the coil. The ignitor itself might be bad - some places like AutoZone can test the ignitor.

16:
Each injector has a 2-wire plug. One of those wires is the same color on all 4 injectors. That wire should have 12v all the time when the key is turned ON. Check whether that's OK.

And do the starter fluid check too.

For what's it may be worth, I made a video of the code(s) blinking: MVI_2037_zpsc743b327.mp4 Video by sgull1 | Photobucket
Here's another photo of the cracked sensor I've mentioned (pointing with pen): http://i207.photobucket.com/albums/b...psacf2eab4.jpg
And a couple photos of the crack(s) I discovered on the rotor:
http://i207.photobucket.com/albums/b...ps8e36b64e.jpg
http://i207.photobucket.com/albums/b...ps783319c6.jpg
When I do the test where I spray starter fluid into the throttle body, am I pointing in this photo to the air intake tube (big black plastic tube) that I'll apparently need to remove in order to spray into the throttle body? http://i207.photobucket.com/albums/b...ps30664327.jpg

The crack is serious enough to cause a problem allowing spark to short to ground.

I think the problem you had w/ installation may be caused by not opening a set screw on the rotor. Set screw holds rotor to distributor shaft after installation. Some rotors press-on and some have set-screw retainer.

You have read the Obd1 codes correctly.

good luck

Okay, I'll at least see about getting a replacement rotor for the cracked rotor. I'm assuming you're referring to the cracked rotor maybe shorting to ground and not the other cracked part (sensor I guess it is) shorting to ground.. I'm almost positive my rotor is the press-on type, no set screw, but I'll take a double-check on that. Also, my last question in post #7, about the throttle body, do I gotta remove that intake tube there, to squirt the starting fluid in to do that test? Thanks!

LIft the air filter cover and spray in at that point. Leave cover loose in case you need to repeat. A good long spray! If this doesn't cause a brief start, then ignition is definitely the problem.

Another way would be to remove the air intake to valve cover, PCV air intake. Simply pull it out and spray into duct at that point. It's in the pic you posted about midway.

good luck