Thought I had thing fixed but set the SeS light again with code P0304 cylinder 4 Misfire.
New Cap Rotor, Spark Plugs. System had Case Relearn and cam retard. Also put on new fuel filter.

2001 Blazer 2WD, 4.3L.

Autozone scanner recorded freeze frame data. Wondering if anyone can make heads or tails from it?

Fuel System 1
Open Loop
Fuel System 2
Open Loop
Load Value
23.1 %
Coolant Temp
105 deg F
Short Term Fuel Trim 1
-5.5 %
Long Term Fuel Trim 1
-1.6 %
Short Term Fuel Trim 2
-2.4 %
Long Term Fuel Trim 2
-1.6 %
MAP Sensor
19 in. hg
Engine RPM
1791 RPM
Vehicle Speed
32 MPH
Air Flow Rate
4.89 lb/min
Throttle Position
25 %

 

Check out THIS THREAD for more information on the misfire codes.

Seeing as how it is localized to one cylinder, have you pulled the plugs and assessed the health of the cylinder vs the rest of the engine? Not to scare you, but I have seen leaking valve seals cause a misfire if one cylinder is leaking more than another. The oil fouls the plug and can trigger the code for that cylinder.

You may also want to check out the P0300 Explained thread I compiled from book references. All references to the code for specific cylinder misfires point back to the generic multiple cylinder misfire diagnostics so that should cover what you need...

 

I assume you changed plug wires with a good set? I don't know about anyone else but I like to use a di-electric grease on the wire ends. For one is keeps the boots from getting stuck on the plug. Second it water proofs the connections. I have done this since the 70s when HEI ignitions came on the market.