I have a 454 in my motorhome. Until recently, it would pull my 20' sailboat (2500lbs) up grades without much noticeable loss if any. Now, without any trailer, it is having all kinds of problems. Lack of power with a slight surging, especially toward the top of each gear (sometimes won't get over 45mph on very slight uphills). Doesn't want to upshift (you have to take your foot completely off the pedal, sometimes). Also, sometimes will downshift quite early with just a slight grade or acceleration (immediately causing the powerloss and slight surging issue when the RPM's go up). RPM's seem to hang higher than normal (sometimes) while decelerating (like its in too low of a gear), instead of coasting in highest gear avail. Seems worse at operating temp, not so much when "cold" (100 deg here in AZ). The code reader stated an Oxy sensor, so I replaced both. Now no codes. Also tried fuel and air filters, with no change. Plugs, cap etc are maybe a year old.
Sep 18, 2008 at 3:10 PM
