OK guys, I am out of ideas here on this truck. It is a 91 chevy truck with the 350 (5.7) with TBI. The truck has 190K miles on it and runs fine other than a misfire.
It does it sometimes at idle when cold and does it just going down the road at 40-45mph when it gets into overdrive and is running in the 1500RPM range. It does not seem to do it when accelerating and I have not seen it do it at constant higher rpm's. Buy "seeing" it, I mean the tach needle jumps a little when it does it and I can hear it in the exhaust. So when it started, I figured it was due for a tune up and since then I have changed the distributor, cap, rotor, plugs, and wires and it did nothing! It still has the same problem and I cant figure it out. I checked timing and fuel pressure and everything seems good. I checked for codes and there are not any. Ideas?
It does it sometimes at idle when cold and does it just going down the road at 40-45mph when it gets into overdrive and is running in the 1500RPM range. It does not seem to do it when accelerating and I have not seen it do it at constant higher rpm's. Buy "seeing" it, I mean the tach needle jumps a little when it does it and I can hear it in the exhaust. So when it started, I figured it was due for a tune up and since then I have changed the distributor, cap, rotor, plugs, and wires and it did nothing! It still has the same problem and I cant figure it out. I checked timing and fuel pressure and everything seems good. I checked for codes and there are not any. Ideas?