1970 GMC C2500 engine miss

1970 GMC C2500
126,000 MILES • V8 • 2WD • AUTOMATIC
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PLUMBDESIGN
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  • 1 POST
I purchased this truck a few years ago with the intention of fixing it up; this is not a road worthy vehicle;
I 've recently replaced all the basic stuff (plugs, wires, cap, rotor, points). I still have a significant miss in this engine (402BB).
What is the most likely cause of the miss, flat spot on the cam or stuck valve?
Jul 22, 2009 at 10:36 AM
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RASMATAZ
  • ✓Experienced Mechanic
  • 75,988 POSTS
1970 GMC C2500 engine miss

Misfires can be caused by worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel
Jul 22, 2009 at 10:52 AM
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