I have a 98 chevy blazer 2 door 4.3 5 speed. I have had a p0300 code for a while now. Come to find out the gear on the distributor was bad, changed the distributor myself along with full tune up. About a week later i had the dreaded p0300 code again along with alot of other codes. Supposedly i put the distributor in a tooth off so it set all these codes off. Took it to a shop had them set the distributor right, the only problem they had to guess to get the distributor right just like myself but of course the mechanic is alot more experienced then i am. So finally he got it right (from what he thinks) and it ran perfect. Maybe a little skip every now and again but nothing too terrible. About a month later the skipping started again, checked code, again p0300. I visually checked everything and my ditributor cap was cracked from the mechanic constantly taking it off and putting it on to get the distributor right. Put a new ac delco cap on and misfiring gone once again. So guess what, a week later out of nowhere i got a p1345. WTF?!?! Before i go tearing things apart or throwing money at it i would get some advice. Sorry could not find any other threads that had the same as my issues cause most of thier 4.3's wont start. Mine starts up runs with a rough idle. Any help would be greatly appreciated!!

 

P1345 usually means the distributor is off a tooth. Cam retard should also be checked once the distributor is set right.

 

 

im guessing the rotor is good?your problem sounds similar to mine atm- im currently trying to get my 2000 blazer 4.3 running right after replacing distributor so if you fixed your issues please inbox me so i can ask you about the misfiring im experiencing, i have 3 different distributors one is new , ones new looking,ones used but functional that is what i removed in the start.

 

7 year old thread. Closing it now.