Have a 1999 Honda Accord that will sometimes not start. When this happens the car turns over almost indefinitely but will not fire. Had the fuel filter and fuel pump replaced (which they now say WAS bad... but not the problem) and after they did, it worked for a couple weeks then started doing it again. They now say it is POSSIBLY the PCM which is around $600, too much for a POSSIBLY I think. So does anyone have any ideas? Thanks in advance.

Perform the tests outlined in sections A and B below:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-46563.html

Have a 1999 Honda Accord that will sometimes not start. When this happens the car turns over almost indefinitely but will not fire. Had the fuel filter and fuel pump replaced (which they now say WAS bad...but not the problem) and after they did, it worked for a couple weeks then started doing it again. They now say it is POSSIBLY the PCM which is around $600, too much for a POSSIBLY I think. So does anyone have any ideas? Thanks in advance.
There is what's called an igniter inside the distributor about 125.00 I had a 1993 accord that stalled after running hard to restart unless it sat for a few minutes signs are if your tachometer bounces around erraticly my mech gave me a good one to try ran fine after than I swapped out for a new one

I had a similar issue. Drove car around, ran fine. Left it in a lot for 15 minutes, came back, started, then died. Never would start after that. Cranked over just find but not a single sputter or pop. Had it towed to my home. First tried to determine whether it was fuel or ignition. Sprayed starter fluid into the intake, no go. Pulled the spark plug wire and put a screwdriver in it, laid it next to the valve cover... bingo, no spark. Now I knew the ignition was the issue. So I pull the distributor cap and see lots of corrosion around the points. Connected a wire from the "ignition module post" to near the engine valve cover, bang... got a nice white spark. So I know the coil and the ICM are good. So I replaced the rotor and distributor cap for a total of about 35 bucks and 20 minutes of my time. Fired right up and now runs like a top. Hope this helps others with similar issues.