I have a 95 Blazer with a 4.3L engine. I have replaced the plugs, wires, cap, rotor, fuel filter, fuel pressure regulator (it was leaking), and the plugs again after the regulator. It still has a miss, and needs to be smoged ASAP. Any help would be greatly appreciated. Thanks.

 

Is it a random misfire or on a specific cylinder? What brand did you use for the tune up?

 

It was a P0304 and now its just a random missfire. I used AC Delco parts, and all the plug wires are on properly.

 

Im hoping the CEL will stay off long enough to get it smoged, but if it comes back on I will be replacing the coil to see if that helps. Come on guys anything helps.

 

Finaly got the check engine light to go off, I replaced some more vaccum lines. It had a bad vaccume line to the charcole canister. Drove it around got it smogged and found out that the HC at idle were too high.Any body have any Ideas on what to do? its the only thing that made it fail.

 

http://www.smogtips.com/failed-high-hydrocarbons-HC.cfm
This link should help explain what's going on.