The engine has great compression and no leakdown.. still has a misfire at idle only and the SES light only comes on if im sitting at a long red light then it goes completely off again when im driving it for a while..I cant think of anything else mechanical unless its a bad lifter, but the engine makes NO noise so im not yet convinced it's that. As far as an electrical issue i have Not replaced the Dizzy , cam sensor or the crank sensor...I just dont want to keep throwing money at this if those parts are not the answer. I can change the lifters out in about 3-4 hours if i had to but if thats not it either i'll be one P*** person lol

 

I've tried just about everything I can think of, same symptoms as yours have changed just about everything except Ignition control module and Crank sensor because I'm not having any stalling problems Let me know if you hear from PaulGGoo I'm about to give up and just live with it, The only other thing that happens is sometimes when I start up the truck I doesn't even take a full crank to start just starts as soon as the key is turned?? My father Has been a GM tech for over 40yrs and hasn't figured this one out yet said to wait till it gets worse because it's not real a full misfire It's a light skip so it's hard to determine what it is

 

I spoke with the service manager at the local dealership about this and they just had a similar problem with a misfire on #6..This vehicle was also a 4.3L blazer with all new parts..They Tested everything and it all checked out good,they were stumped too, then just for the hell of it they put an AC Delco cap on it and the problem was solved..They inspected the other working cap and could not find anything wrong with it. Maybe that's what i will try next..If it don't work i will have 3 extra caps for my other tune-ups lmao

 

let me know if it works!!

 

will do for sure!

 

I have about 4 aftermarket caps laying around too !! LOL!!!

 

This is and interesting thread. I too am fighting a P0304. Changed plug and swapped plug wires (2&4). Next I’m going to swap an injector. I didn't think a CASE learn was required on these engines?? And oh ya I've got Delphi cap and rotor do to corrosion on pervious cap.

 

so i take it the cap and rotor didn't help? I still haven't tried an Ac Delco cap...My SES light comes on intermittently ,the rough idle is still there but not as bad as it was in the beginning.I'm so used to it now i actually worry when the light goes out if the bulb hasn't blown .. lmao!

 

Ok Ive just read all the threads and im gonna throw an idea out there. I had a friend with a 2006 mustang gt and it had very low miles and ran and sounded great! We where both mechanics at a pepboys. We had checked everything under the sun and no one at that shop had figured it out, The car was still under warrenty. So he took it to the dealer and they couldnt figure it out so then the dealer called some bad *** ford big wig tech. and he came and found that there was something from the altinator cousin the ingine to have a slight mis. They replaced it and it went away.Its just a thought I see yall whackin brains.

 

i replaced my alternator and there was no change