In the process of replacing my timing cover and gasket I also noticed that I had a small leak on the lower manifold gasket so I removed the lower manifold and replaced with a new gasket. When I started it up I noticed that I had a slight miss. When I took it apart it was running fine just the water leak and I now noticed that I get a sulfur or gunpowder smell that I didn't have before and when I hold the rpm's at 3000 for a while it will climb up to 4000-4500 rpm's and then back down. No codes have been set but still have the miss. I checked the plug wires and plugs all ok, the compression was 185 on all cyl. and as far as I can tell all my connections are plugged in. Any ideas what might be causing this miss? Thanks

 

Quick question, when I went to start it up for the 1st. time I had crossed no. 5 & 6 wires so it bucked, banged, and coughed before I straightened out the wires, by chance could it of bent one of the push rods enough to cause a slight miss?