OT: Truck Won't Start in the Morning, "Cold" Start Issues Options

[Nogoodwithusernames]

Way off topic I know, but this forum is also WAY better than others that would maybe be more appropriate for this.

I've got an Isuzu Hombre '98 4 cylinder pickup. It does have a bit over 200k on the odometer, but it runs good. This last winter it started acting up not wanting to start in the morning. I'm in CA so morning temps can range from 30°f upwards just depending on weather.
It has gotten steadily worse where to now it won't even start when it's 50° outside.

I have tentatively narrowed it down to lack of spark, it will crank and crank and crank but not fire. A timing light on a spark plug wire while cranking will not flash.

I started with new coils figuring those might be going bad and not wanting to fire when it's cold out. No dice.

I am also getting codes for cam and crank sensors (as well as codes EGR valve and low efficiency on CAT, though I believe those are unrelated to the no start, and I believe the one caused the other so I cleaned out the EGR and made sure it was moving freely and seated okay, and have some BG 44k in the tank to help clean things out)
Anyways replaced the cam and crank sensors with NTK brand and it started two mornings in a row, and now won't start in the morning again.... Temps were all about the same all four mornings.

It will start just fine later in the day though.

Of course with all of this registration renewal is coming up and it's a SMOG year (IMG:style_emoticons/default/headbang.gif)

Any troubleshooting tips would be appreciated since it feels like I'm (IMG:style_emoticons/default/dead horse.gif)

[Nogoodwithusernames]

Thanks for the responses folks, good to get some feedback and help keeping me from pulling out all my hair. I'm only out $150ish so far in the "throw parts" department, but don't want to continue if I don't have to.

Sorry I did forget to mention it is identical to the Chevy S10 and GMC Sonoma, just a different emblem. In fact the wheel covers have the Chevy logo on them even.

I'll look for a shop manual and in the meantime this thing may just end up on non-op until I can figure it out.

I do have a decent DMM and some needle pin leads so I can go through all the harness with time.

It is just throwing me for a loop that something temperature related would cause complete lack of spark. ECU might well be the culprit. Maybe I should convert it to D-Jet.