September 16, 2009When driving, usually in the 1700 - 2000 RPM range, in any gear I would get a wicked misfire/ backfire. No "CHECK ENGINE" light. I have replaced:
1) NEW GM crate engine (old engine toasted some bearings)
2) changed distributor (old one had a worn drive gear and busted tab for the cap)
3)changed CAM position sensor 3 times
4) NEW cap/rotor/wires/plugs
5) gutted the cats and installed a MagnaFlow cat back system
After all this, the engine still has this misfire. I took it to a local shop that I trust. They found a busted/corroded wire going to the distributor. They fixed it and told me it was fine,
The truck still does it. Not near as bad as before, and higher up in the RPM range, but you can still feel it, and hear it in the tailpipe. Also it seems to idle a little rough, and hesitates when you first apply the throttle. Now, the "CHECK ENGINE" light will flash telling me about the misfire, but no other codes. I've spent a pile of money on this thing, and need some help to figure this problem out.