OK, you guys 99% of the time come through So heres my problem. I have a 97 f250 HD with 460 automatic. Last couple months it will not start when raining or damp..{live in buffalo ny, happens often}..Of course changed cap,rotor(MSD),wires etc, no luck. When i do finally get it started, it runs great. Well i decided too change distributor too. Now when i get it started, it runs terrible, misses, exhaust smells, and throws a p0300 which is random multiple misfire. Timing is set at 12..(tryed 10 too)..with spout out, firing order is correct. My question is could a defective distributor cause that code? Also the MSD coil is about 2 years old. Possible that would go that quick? I used one of those pen looking spark testers you just touch the wire with and it shows orange glows. Are them things even good enough too show a blue spark? I dont want too really buy another distributor just too see due too not having a core now..(napa...$70.00 core charge). Just wanted too see if you guys think it could be defective and cause that p0300, or could it be something else i could of hurt trying too start it so much when wet..(lotta popping and chugging)....and the distributor didnt help the wet starting either, but gave me this new problem. Would i have too reset pcm after dist. change? Im wearing down my finger and getting a bald spot. Hope you guys can help................THANKS

 

A couple of thoughts, Is your timing light capable of checking the computer advance...I had similar symptoms with a new Cardone rebuild, so distributor could be faulty...you did not mention if you replaced the spark plugs...and welcome to the bald spot club

 

sorry been busy and couldnt get online till now, thanks for responding. yes i did change plugs too, first auto light, now ngk v groove, whats weird is both sets are like brand new when checked....white with, tiny ting of brown grey, hardly noticable....no fuel soaked, or anything, all great shape.
yes do have timing light with advance, but left at zero when timed.....so you had problem with cardone too? gonna try too get another, let ya know......thanks...kinda figured distributer was junk, but was iffy bout changing it, hope advance auto will give me another, because if i take this one back and get new from napa, im out a core cause they already got rid of mine.....napa wants $69 with $87 core charge..(interesting huh)...so guess ill be paying $156 plus tax now cause cardone is junk.....thanks again

 

3 of them in a row...finally bought a CarQuest NEW not rebuilt heat tested unit, no core exchange needed about 120.00. My advice would be if you are gonna replace it, to buy only a heat tested one.

 

Thanks, you were right, changed dist. and runs great, but still wont start when rains,snows, or damp out...(which sucks cause its my plow truck). its getting spark, but when i do gat it started,,,(hours and dead batteries trying),,,starts and runs great...something getting wet....and never another electrical part from advance auto

 

every time mine won't start on a wet day is it's the coil wire
but you said you changed wires~~~