Thought I fixed my misfire...
 

Well after numerous times searching this site and reading multiple threads, I can't seem to find out what is wrong here. My 2000 2wd had a terrible misfire. After just throwing money at it (I know, stupid me), I finally found this website and did some research. Well after changing my distributor (among a bunch of other things), I thought my misfire was finally gone. Wrong. I drove it for probably a week before it came back. After it rained one night, I got in it to go to the store in the morning and there it was. Only for about 10 minutes tho. After that, it ran fine once again for a few days until we had a cold day a couple nights ago. There it was again. Only for about 10 min. again. Now today it's raining and a bit chilly and its back again. I just don't understand. Can any give me some ideas on what might be causing this misfire when it's cold outside or raining?

Parts ive changed include
Crank pos. Sensor
Cam pos. Sensor
Plugs(Ac delco)
Wires, Cap, Rotor(before the distributor)
Distributor(used, but known good)
Egr(used junkyard)
Coil(used, but known good)

I have a 93 Blazer. About the same thing happened to me, from about Nov., til around March. Had a miss I couldn't get rid of, Of course it was cold during all that time. I replaced everything in it, didn't help, always missed bad at medium speed. I had replaced the plugs with Autolite, and the wires with Bosch. I read enough in other posts to find out I should have used Ac Delco for best results. So I replaced the plugs and the wires. Haven't had a miss since..
BTW, the whole time I had the miss it started great, ran great, until about the time it shifted into high, then started missing, even when I slowed down.

Ok, so I changed the cap, rotor, wires, and plugs with all ac delco, and my misfire is worse now. It always misfires rather than just when cold or wet outside... Idk what to do anymore. As much money as i have put in it, I cant really see myself selling it. But i'm about to that point. Any ideas would be much appreciated...

Should I just take it to the dealer and see what they find? Can't really afford it, expecting a baby in this next week. Just really need to get this fixed.

Mines was doing the samething but i have a 02 blazer all i did was get a can of maf cleaner and turn on the car and spreyed some on air hoses and that was the issue seem like i had to change all my hoses to get it to stop

To go from bad misfire to Worse misfire using name brand parts, sounds to me like it may be a crossed spark plug wire.. Is the truck giving you any service eng soon lights? My Blazer rec had a misfire under load only, I wound up getting the dreaded P0300 code, ( Random Misfire) I came home and disconnected the neg batt term for ten minutes, the code did`nt disappear, i disconnected both terms and the code was still there. I finally found to have a badly corroded cap and rotor ( AC Delco) which had roughly 29,000 miles since my last tune-up. I replaced both items with AC Delco parts and bam no more misfire and the code cleared up..I bought one of those "car md" scanners like ya see advertised on the forum here, it gave the codes desc and what to do to fix it and the cost of what it would be to repair it... All said and done did it myself $60 in parts. dubble check that ya dont have the wires crossed at the cap or plugs, if ya need the firing order i can send that to ya. make sure the plugs are gapped at 60. If i lived closer to you i`d help ya.Good luck with it, keep us updated and congrats on the new family member..If you`d like you can email me PM me for any help.